I've a nice big old glass pipe I use - it's cruddy with tar from weed .
Mos of the time I just soaked it in Isopropyl. all the brown goo comes off the glass.
But I'm out of isopropyl and my now it's a sticky mess - what else works?
That goo is THC laden resin.
Scrape it off and smoke it, dumbass!!!