Don’t bother cleaning with steel wool (or more boiling water).
1. Acetone or nail polish remover
2. Lighter fluid
3. Isopropyl alcohol or
4. High proof ethanol (160 proof or 80% abv)
it’s a chemical issue, so attack it with chemicals. Either of the alcohols is a safer option, but the first 2 would work just as well.
Tom
edit: I see others have mentioned alcohols. better living through chemistry has been my motto since college

I’m not too ashamed to admit that years ago I disassembled a build-a-bong, placed the pieces in a pot, covered the pieces with heavy cream and simmered it. Didn’t clean it, but enough cannabinoids were extracted to make foul tasting hot chocolate.