I've done a decent number of mescaline HCl extractions (mostly from San Pedro) and have used both xylene and limonene as NP solvents. IME I've noticed a big difference in the final product depending on the solvent used (even after acetone and IPA washes). In my experience, xylene has given cleaner extractions as well as a higher yield of purified, washed mescaline, while limonene tends to pull a lot of salt with it and not as much mescaline/alkaloids. I'm curious if others have also noticed a difference between solvents, or if you prefer one solvent over the other and why?

My experience with this:
I started out using xylene for extractions but decided to give the limonene a try since it's food safe (and doesn't smell awful). I was initially optimistic; it seemed like my salting yields were decent and I was able to do more salting pulls while still getting what I thought was mescaline/alkaloids. However, after doing an acetone & IPA wash on the extract, the cleaned product had a very noticeable salty taste (as well as being somewhat bitter). After taking a weighed dose it was definitely apparent that the effects were considerably weaker than the mescaline I'd extracted using xylene as a solvent.

After removing the NaCl via boiling IPA I found that about half the weight was salt, leaving me with much less purified mescaline than if I'd used xylene (same dried plant source used in both cases, with xylene I can get usually get around 1% but with the limonene it was closer to 0.5%). I used the limonene for 3 or 4 different extractions and the result was the same each time. As soon as I switched back to xylene, I was again getting better yields of very bitter, clean mesc HCl. Have been using xylene ever since with no problems.

One possible cause could be that I used 95% pure d-limonene, whereas in retrospect I should have used a higher purity

So I'd like to know if anyone else has noticed limonene pulling salt/other contaminates like this? I know a lot of people here use limonene, so to those that use limonene have you noticed a salty taste to your extract? or is it always very bitter as it should be? Is limonene commonly used simply because it's food safe, or has anyone noticed an advantage to using it over xylene?

I've never used xylene, but I can agree with you about limonene by comparing it to my experience with everclear extraction. But I'll go further by saying that even simple tea extractions produced stronger results than limonene.

I have extracted twice with pure, 100% food grade limonene, using moderate quantities of san pedro (pachanoi). The first time was with two feet of three inch thick pachanoi. By testing with a tea extraction of another of the same two feet, it should have produced a level 3 trip, but with limonene turned out to be a .5. I thought I screwed something up.

But the second time I extracted with more than twice as much--four feet of huge four inch thick pachanoi from the same vendor--with the same disappointing results. I tested half of it full spectrum before spending the time to wash the other half. The first half turned out to be another astounding disappointment--so weak (another .5) that I'm not going to waste my time and effort on the second half. I'm not even sure it will be worth taking, so it's just sitting there. If I want to microdose on two feet of four inch thick pachanoi, I'll take it.

What HAS worked very well for me is pressure cooker tea and everclear, so far. Pressure cooker tea is so salty and bitter that the very thought of it is making me nauseous as I type this, but it works very well. If you can choke that down, you're good to go, except for the inevitable heaving that you'll get during the comeup.

Everclear has been the best so far. Produced great results with little-to-no nausea, which is a big win for me right there. No inevitable purging required, like with raw or tea methods.

xylene.

purest crystals I've ever obtained was mesc sulfate, salted xylene.
m.p. range within 1C of lit.

Sounds a lot like my experience with limonene extracts. Took 600mg of limonene extracted and cleaned mescaline HCl (except for cleaning the salt impurities which I learned afterwards) expecting a pretty far out journey, and it ended up feeling like ~300mg. Still a strong trip no doubt but I was really prepared for much more. Never again limonene.

So what do you do with your everclear then? Do you just evaporate it away to get a resin?

I prefer toluene over xylene...
They're both pretty potent smelling, but toluene doesn't smell as foul as xylene. Overshooting a titration with too much acid when salting will lower the potency of your product no matter what non-polar solvent you use.

Yup. It will evaporate pretty fast to a thick dark green resin that doesn't seem to dry. For a fresh experience, spoon up some and stir it into strong coffee. Scoop up the rest into caps, shot glasses, or clean it. That will be my next step--figuring out how to clean the alcohol extracted resin. Or the pressure cooker extract. One or the other. They both can produce a very strong full spectrum extract.