Fuck pressure cooking and fuck shrooms!

put the top on, then foil, then screw down lid... i never had a problem... another way ill do it is... wrap whole jar super tight with foil

I'll try adding foil on top and screwing the lid on that seems like it could work, I have tried to completely cover jars with foil tighly and it still got in somehow.

if that doesn't work, you have some seriously bad mojo.
Just get some pre-made bags.

you need a layer of verm in the bottom of your jars to wick up the drips. Make sure to cover the vent holes by wrapping jar tops in foil, to stop water going in there... don't overfill the pot with water, the steam does the work, not the water.