At Neb's house (the derelict house) in the Bridge District, there's a trapped and locked painting that emits paralyzing green goo EVERY time I try to disarm it.

I even hacked up my thief's find/remove traps ability and still failed.

Is there any way to disarm it?

I have never disarmed that trap. It has always been too difficult for my thief :( , so just take stuff from painting and suffer consequences.

Such a strong trap...

There is only some gold in there right?
I forget.

There wasn't anything important in there. Perhaps gold, but I'll never forget the potions of extra healing in there. I always have to use a few afterwards!