I’ve carried a firearm on a regular basis for a decade now, for most of that time a Glock 19. During that time I’ve never had an issue with what to do about the gun in the john. I’ve found it’s possible to use a urinal without dropping the drawers far enough that the gun drops below the covering garment (though I usually prefer a stall when carrying), and the number two situation can be dealt with easily, if you’re using a proper holster, by not dropping your drawers around your ankles. Taking the belt down to just above the knees is enough to drop your friends off at the pool, and to keep your firearm out of sight and under your immediate control. A proper holster will stay on the belt regardless of whether you’re wearing it or not, and will retain the gun even if you hold it upside down. The only thing you have to be conscious of is to make sure the belt doesn’t side out of the loops, but I’ve not found this to be a problem with properly sized belts.
I think advice that suggests unholstering the firearm is bad, and I wouldn’t suggest anyone follow it. If Â you do find it necessary to remove your gun in the john, or anywhere in public, remove the holster while the gun secured in the holster. If your holster won’t do this, or if retention is a problem, time to rethink your holster. The best advice is always going to be that which keeps the firearm secured, and minimizes the chance of something, booger hook, piece of clothing, or door coat hook, from yanking on the bang switch. I’m of the opinion that, ideally, the only time your firearm should clear leather (or Kydex, as the case may be) in a public place is if you have to defend yourself.