I sense a "Niche" market here. SHOWER GUNS!!
Designed to be permanently kept in the shower, ready for use. Totally rust and corrosion resistant.
Then there will be holsters, also moisture proof, in various configurations for securing to shower curtain rods, shower head or where ever.
Don't for get magazine carriers and special moisture proof ammo.
Other accessories come to mind. Non-fogging safety lenses, water/soap resistant hearing protectors....the list goes on...