Hello. Apologises If This Isnt The Right Fourm, My Friend

Hello. Apologises if this isnt the right fourm, My friend uses meth-amphetamines and idk why the fuck hes wondering but he would like to know if the build up of crystals in his nose would still be safe/good to use/smoke if they came out clean XD
as he doest have internet, ive decided to play devils little advocate. Thank you all for your time, any serious answer is very much appreciated.

Stay safe & Remeber! Dont do drugs!