“What is your standard shower gun? lol”
Mine is a stainless steel wheel gun, strategically placed. A bathroom is the ideal low budget “panic room”, all you need is a solid door, a good lock. a firearm and cell phone. The tub also provides some protection, if it fiberglass you can put steel plate in front of it and box it in.
I recommend you do not place it in proximity to your hairbrush or blow dryer. :-)