I got curious of my cheap PP's ability at waterproofness. I filled a five gallon buck with water, and since the water was cold I put my PP in the fridge (did not want to risk pressure/temp difference).
After the PP chilled I put it in the bottom of the bucket for 2.5 hours. Before I completely removed the PP I thrashed it around in the water for about 10 seconds. Then I accidently turned it on forgeting the battery was in it, and it fried because of complete ingress of water. J/K
Any before I put it in the fridge I put a wad of toilet paper into the inner most battery holder with some tuffs sticking out into the cap area (making sure not to interfere with threads). When I took it out of the bucket I thoroughly wiped the outside dry with a towel so no outside water gets in as I unscrew the cap. I opened it to see there was visible water (though minor) admissioned in the threading. The inside cap was dry, the tissue was dry in the battery holder, but the outside facing the cap was mildly damp.
I have teflon tape on the threads, but not on thick. I closed the cap finger tight. I fear of wrenching it on even though it does compress the o-ring more, but I'm babying it. I can get silicone for around the o-ring, but if I do actually bring it in the water it will either be momentary (rinse, or shallows), or in a zip lock freezer bag aka Trojan (don't use lambskin).
If my Far East pointer helps to make some good finds? Then I'll holster, or sling a Nokta Mini Hoarde as my pinpointer. This way when people see me they'll know right away that I'm an expert. And I have a PP for loan, or as backup.
Sorry for blurry pics.