Might want to re-think that "rubbery tool handle" trick. The one I use, Plasti-dip, does a great job in many applications. BUT..and a BIG BUT..: it must be somewhat gas permeable because in a Zippo lighter so dipped the fuel evaporated anyway. And iodine tablets in a soda straw..totally dipped in multi-layers of Plasti-dip outgassed and corroded nearby metal anyway.
I couldn't believe this, because the plasti-dip did create an evidently waterproof seal. But lighter fluid and iodine got through it.