The best, simplest way to purify any street amphetamine or methamphetamine is the following:
1)Get some acetone (paint remover) at your local hardware store. Get some coffee filters and a plastic/nylon filter.
2)Dump your amph/meth powder/crystals into a coffee filter in a filter. Put a glass or jar underneath the filter.
3)Chill a couple cups of acetone in the freezer for 1/2 an hour or so and then pour a cup or so of acetone over your amph/meth. The drug won't dissolve in the acetone, but many of the cuts will. You can stir the stuff (drug + acetone) up a bit to make sure everything mixes.
4)Let all the acetone drip through, then wait for your crystals to dry, and throw out the acetone that dripped through. Your resulting amph/meth should be much purer/cleaner.
You could recrystallize, but the product you'll have after your acetone wash should be just fine for most recreational purposes.

[ 01 December 2002: Message edited by: fairnymph ]