I thought I made a thread about this, but only a few mentions in the search, including a vid.I used a probe to clean up crystals, but an ultrasonic bath also works (just used one to good effect). Cavitation bubbles act as nucleation sites, resulting in aggregated (albeit smaller) crystals. I think this would be a good way to resolve supersaturated solutions (goo, residue, etc)...hexane and an ultrasonic bath.

seriously...if you don't have an ultrasonic bath, get one. besides being useful for cleaning glassware, jewelry, and machined parts, it resolves residue and grows crystals effortlessly. It's almost like cheating.

the bubbles create aggregated localized areas for crystal formation; it's as if the bubbles find similarly arranged molecules, and piece them together. It's also a great method to clean up dirty crystals, which I originally used a sonicator for(cleaning san pedro-derived mescaline salts).

this is similar to the bath I have, a Branson 1510. nothing major, 1/2 gallon, 70 W.

Seems like a nice to have. Could a setup (a cold bain marie) as in the picture attached work, or are there better ways to use the sonic machine? Was wondering if the sonic energy could replace the deep freezer.

it won't replace it, but it will expedite the process. as the opaque solution begins to cool, put it n the sonic bath for a couple mins.. you will see aggregates of crystals begin to form on the side/bottom of the jar. then put the jar in the freezer for a couple hours (the process I described translates to ~8 hrs in the freezer).
and I'd put the ice in another container, along with your container of naphtha. Sonication does generate heat, so it will melt the ice to some extent.

I don't know why I didn't think of this before, would've saved a lot of time and energy: say you have a residue in a glass container left over, that just won't crystallize...
add the nonpolar solvent, and place in the ultrasonic bath for a 2-5 minutes. that nonpolar solvent will be cloudy white, ready to freeze precipitate. *edit* actually, I just realized...there will be microemulsions, bubbles containing both phases. it will need a bit of separation in the second container (which more sonication will resolve).

sonication speeds up several processes (which is why it's used in redox rxns too), including migration of molecules between phases.
with a strong enough generator (i.e. a cell disruptor with a probe), you can lyse cells. but a bath is sufficient enough for other extraction processes, and cleaning up the glassware.

aside from glass, there are four pieces of equipment I feel are essential for a serious chem hobbyist: a hotplate/stirrer, a vacuum source, an ultrasonic bath, and a rotary evaporator (optional, but makes life much easier, like a Kitchenaid to a chef). some would argue a centrifuge, but I rarely use mine.

Thanks for the great tip, catching up on my post-holiday reading. You've already given me (loving and respectful) Rotovap envy from your pic in the pretty pics thread