ok heres what i found fourmala 420 and other such products are basicly isopropyl alcohol and an abrasive and an essential oil that gives it the good smell

so

best method ive found is

1.highest % isopropyl alcohol you can find
2.some absasive any type of salt/rice or whatever (be careful of things that are to harsh like sand)
3.lots of hot water before and after soking/shaking the iso solution

~Russ~