My IWB holster has a leather backing, I wear an A shirt every day, under whatever I'm wearing. My gun will still be moist and the end of a summer day. I just clean it once a week, and make sure it all works.
The reason I say this, is because you shouldn't need to constantly "change up" your carry option. Stick with just 1 way, that way your tool is the same drawer every time, and your not feelin around for your gun like you lost your car keys.
Also, your gun may get wet. It happens. You shouldn't worry about it, honestly. Just keep it clean, and lubed. Glock monday-saturday, kimber on sunday, isn't that how it goes?