greasy speed could be methcathinone. which is made with articles found at your local grocery and hardware stores. and it's shite.
i'm not sure how it affects nasal absorbtion, though. what about coloring?
washing it means, put it in a jar, dump the speed in, dump some acetone in, get another jar, put a coffee filter over the jar, pour the acetone SLOWLY into the coffee filtered jar.
I've heard quite a few people talk about acetone and washing your speed.
What is it used for apart from washing speed?
Does it work on base speed?
Can I get it in the UK?
Cheers.