I give all my trim to my mate, he makes bubble with it then brings a bit round for us. TBH mate, it just sits in a bag for desperate times.. They haven't happened for years tho so there's a fair bit kicking around the house. It's a bit 'arsh tho innit!?
I've done it with him a few times... (Made hash) there I go again...
But yeah, that's as technical as I've got with trim recycling.
I've seen the butane one done in a plastic bag before, looks easy, just not particularly up to H&S regs.. If ya know what I mean!