amphetamine is much more soluable in 95% alcohol(if those 5 % is water,wich is the fact with grain alc) so a good deal of amphetamine will dissolve together with your coke.
i've heard something about amphetamine HCl(not crystalisable) is soluable in DCM(dichloromethane,paint stripper) while coke HCl is not.
so you could dissolve youre crude coke in water,add Lye,extract with DCM(water is upperlayer) pour HCl in your DCM(10%) ,shake,extract water layer(upper) and evaporate.
you might want to do an acetone wash before this procedure.
as i said before i dont know if this works,can someone give me a feedback on the solubility of Amp.HCl in DCM
this procedure is getting quite long then,and i dont think most of u will bother to do it.
and to the above poster, No u cant coke HCl will just burn off without any effect, you'll need to convert it to the freebase (crack) to smoke it)