"You first wash it with acetone about 2 times. You use about 20 ml of acetone for each wash. With the acetone covering the mescaline, you small the mescaline and much as you can. You want to powderize it in the acetone. Wait for all the particles to settle down and then carefully decant your acetone so that none of the mescaline is decanted with the acetone. Repeat it with 20 ml more acetone.
Ok, at this point the mescaline is usually very light tan and it's difficult to get it pure white with more acetone washes. So we now wash with 99% isopropyl alcohol one time. We use about 20 ml. It must be 99% isopropyl alcohol. Pour it over your light tan crystals and mix it. Let all the pieces settle down. Now carefully decant the IPA leaving behind pure white mescaline HCl."

Can someone explain this to me a little better?

What is it about it that you dont understand?

By the way I moved to the appropriate section because this is not 'general dmt information'.

Also I edited the thread title, please next time think that in the thread title one should include information about the content of the thread. Threads arent only for the ones making it, they can also serve for those that in the future might also have the same doubts, but thats only possible if the information is more easily visible.

Take dry mesc hcl, add acetone, crush up mesc while it is in acetone repeatedly for 5 minutes, let mesc settle to bottom, then decant the acetone. Add more acetone, repeat. Allow excess acetone to evap and leave you with cleaner mesc. It is best to use anhydrous acetone, and it is also good if you can keep it cold.