I don't. Again, because of humidity.

Being an HVAC technician, I'd just point out that tubs (and houses) don't have lungs, and don't breathe. Basically, you want it to leak is the term.

Even without the press'n seal, my egg tubs are almost at 100% humidity. We tried the plastic on the first tub, and it's nothing but a pain in the butt. We use the substrateless method, so I don't have to worry about too much water escaping.