m0useanswered grow question a month ago Yes Isopropanol, can also try to freezing them and banging them on something to help dislodge the stuff that is stuck in them. but be gentle as the plastic can break.
I would also use a soap and water combo before iso to help get rid of anything else that might be in the bags as well that iso might not remove. Also good idea to wash them inside out and upside down so all the dirt falls out of them and not collecting more into the collection nets, I have eazy access to 99% and 70% ISO, do w/e is cheapest its just going to waist anyway. and use in a well vented area or you will gas yourself.