Loren Pechtel
Explorer
Given longstanding precedent and the fact that leather is basically animal-stuff and cloth is basically plant-stuff, I've always just ruled that the green slime dissolves the crap out of it.
As a side note, a pc in my game way back in 2e started packaging green slime in glass globes as grenade-like missiles.
Yup, green slime bombs are *VERY* nasty.