There's a thick and slimy sludge residue on the sides of the separatory funnel after adding the acidified filtrate from boiling MHRB.
Does anyone know how to dissolve this stuff for easy cleaning?
So far, I've just been rinsing the inside with hot water, but there's still a little residue left...

try adding some naoh solution

Or if you're very good with handling chemicals, piranha solution.

easy there, no need to pull out the big guns and overkill if the job can be done be done with a peashooter.

often its the tannins in the bark that cause that residue, deprotonating their phenols them with a strong base brings them into solution, in addition to other useful cleaning properties of the strong base. Sometimes it needs to be pretty concentrated though to do a good job. Shake up 10mLs of a 50% solution in there, thatll do it

A good way to clean stubborn glassware is to soak it in a solution of alcohol and KOH, strongly basic solutions will even etch glass but not really an issue, even with abuse, ive left glass in base bath for months, haven't had a problem, the thing to watch out for is the ground glass joints, but even those I haven't witnessed any deterioration, even in 20yr old glassware, still holds a vacuum seal. Just don't use it to clean glass frits, for that, if its really clogged, i will use piranha, but its always the last thing i try.

For some people it really was the last thing they ever tried. For rather more, the last thing they saw.

Just some words of caution. Piranha really is dangerous.

Kinda forgot that not everyone on here is a scientist.

You could use a fine abrasive like fine sand, and swirl it around. Its how I clean my bongs, with a little bit of isopropanol and a fair amount of water.

Or invest in an ultra sonic water bath.

Please, spare me. Guess who die from piranha explosions? scientists, or at least, university students... It is far more likely for your average absentminded sleep deprived researcher to blow themselves up making a simple mistake, then it is for your average person... Its all a matter of likelihood of exposure... taking unnecessary risks every single day is just stupid, a mistake waiting to happen.

Its not even about the danger, its a waste of time and resources... the smart scientist is a lazy one, he doesn't use dangerous hot oxidizing solutions of concentrated acids when he doesn't have to, which takes precious time of preparing before hand even if its simply grabbing the bottles of necessary reagents. Easier to just rinse with a bottle of naoh solution, distilled water, and finish with an acetone rinse to dry. All can be done with bare hands over the sink in about 10 seconds without worry about getting holes in your clothes or having to wash your hands.

if you were working in an organic chemistry lab, and had some gunk in your sep funnel and the very first thing you went to clean it with was piranha solution, you'd be called an idiot and be told to use your brain.

always try the simplest thing first, especially in research. The simplest method is the most powerful. Don't overcomplicate what is simple. Don't reinvent the wheel. These are mistakes of the naive student.

For cleaning glassware, my procedure is:

1 - Warm water with dishwashing detergent.

Works wonders on most stuff. Like with the dishes, a bit of soaking helps, a soft brush will give the coup the grace to most dirt and crud. If your particular glassware is incompatible with common dishwashing brushes, invest in a long slender bendable brush. An alternative hack is to use sand. Don't use river or sediment sand (sharp sand) because that will scratch the glass, making it more prone to catch dirt. If you have to use sand, only ever use beach sand.

2 - 95.5% Alcohol.

Available as methylated spirits or as bio-ethanol or spiritus or whatever it is that your supermarket sells. It doesn't matter if it has colorants and additives, those can be flushed with water afterwards. The comments above about a brush apply here also.

3 - Nail polish remover.

Sometimes it comes as nearly pure acetone, sometimes it comes as ethyl acetate or a mixture of the latter with ethanol. Again, and a brush.

4 - Bleach (NaOCl)

Housekeepers' tactical cleaning weapon, bleach has amazing cleaning potential. It is both oxidizing and strongly alkaline. Even though this is very OTC household stuff, we are rapidly approaching the ugly zone now. Use caution and abundant personal protection gear, like goggles and gloves. Don't mix bleach with ammonia or with hydrochloric acid. Each year housekeepers die because they didn't know that.

5 - Try again

If you have come this far, and have removed most dirt, but some pesky crud still remains, try going back to step 1. It might just work, now that the unresponsive blobs are gone.

6 - DCM, chloroform or toluene.

This is where it gets ugly (and stinky). 99.9% of common glaasware stains can be removed with the aid of the above methods and some elbow grease (or patience). If you did not succeed with the above, try them again before your go here.

7 - Ethanolic KOH.

This is where it gets really ugly. If you have to use measures this drastic, consider buying new glassware instead. In any case, use of KOH is preferred over NaOH as the former is a lot less prone to damage the glass.

8 - Try again

If you have come this far, and have removed most dirt, but some pesky crud still remains, try going back to step 1. It might just work, now that the unresponsive blobs are gone.

9 - Accept some traces and markings that will not yield to all your efforts so far.

Just accept it, if all your efforts failed at dislodging some last traces of crud on the inside of the glassware, what are the odds that it will ever come off? Consider it inert, and part of the glass. If the functionality of the glassware is severely impeded by a large accumulation of crud, bin it and buy a replacement. Otherwise keep it and occasionally look at the marking, and try to have sentimental feelings about your past mistakes. Consider it like that tattoo you woke up with after that night when you can't remember how drunk you got, perhaps. At least with the glassware stains, you remember how you got them (unless you made them too while incredibly drunk).

27486 - chromic acid or piranha/caro's acid (peroxysulphuric acid) or similar

Don't do this. Unless, perhaps, you wrecked a 50 cm diameter glass frit while attempting to filter ground rue seeds with it. If you did, just repent and buy a new one, stupid. And don't grind rue seeds anyway. If you still insist on living dangerously and using these lethal oxidants, at least make sure that there are no organic solvents left in the frit, especially acetone (oops...BOOM) Again, simply: Don't do this.