I only shower while camping if I am hot/sweaty in the summer or have been out mountain biking.  Other than that I wait until I'm home.  I do use the toilets at a campground...however, we just recently bought a porta potty.  My wife won't let me use it for #2, although she will allow our 7 yo son to use it.  She thinks with me being a large man, that the toilet won't deal well with my deposits 😀
Jason

We use the CG Showers with crocs or flip flops.  Have yet to run into a bad one.

we've always used CG showers when we had our popups. now that we have a hybrid, the DW prefers to use its shower, over the CG ones.
it doesn't matter to me, i'll use either. i use flip flops into the stall but not in the shower.
after all, it's all soap and water in there! 😀

I'm not going to address using a public bathroom, as I feel that the urge of 'having to go' can greatly affect one's judgement regarding suitable places to relive oneself.

Disclaimer:  The following might be Too Much Information:  As far as showering, I'm one of those people whose bodies NEED to be washed about every 8 hours or so to prevent bad odors and/or hair that looks like it's had oil poured over it.  To me, this is a burden; I wish I could skip showering for a day (or even a morning or evening shower) without looking/feeling like I'd skipped a week or two.

That said, my personal urge to feel/appear clean has (so far, anyway) affected my judgement in choosing a place to shower; it's overshadowed whatever public bathhouse grossness I've encountered.  I always wear flip flops or Crocs; if I must put toiletries down on a bathhouse surface (I usually try to operate out of a plastic bag that I will then reuse for garbage), I try to leave them out in the sun (and/or spray them with disinfectant) till the next use.  I always keep my dry towel in a bag (also reused for garbage); I do not allow it to come in contact with bathhouse surfaces.  The wet towel is hung up to dry (preferably there is sun with its UV rays).

I've been called paranoid by many (especially DH and DS's), but I don't think that my particular precautions are outlandish as they really don't impact anyone other than causing me to be maybe 5 minutes longer in a public shower, which I admit can seem like an eternity to those who might be waiting.

Specifically (again forgive me if Too Much Information) I will shower in a place with mold/mildew (provided I can keep my toiletries/towel/feet from contacting those surfaces and dry/disinfect them thoroughly when done).  I have encountered public showers with feces on the floor (the kind of people who would leave such is another subject altogether); in that case, I've opted to bathe/shave/wash hair while standing in a dishtub in the PUP (although it did create a lot of wastewater for DH & DS's to dispose of). 

For me personally, bugs are another matter altogether.  While camping at Delaware's Cape Henlopen and Seashore State Parks, I've found mosquitoes and spiders in the shower, but also beautiful (and harmless) moths, mud crabs (though if you pick them up by the claw they will pinch), and quarter-size baby terrapins in the bathhouses.  Conversely, while camping in a SE Montgomery PA township park with my DS's Scout troop in 4 years ago, the public toilets were all but unusable due to about 1/2" of millepiedes coating the surfaces of the walls, floors, sinks, and toilets (again, sorry if Too Much Information, but it especially repulsed me to find them crawling up my legs as I tried to crouch above an already-encrusted toilet).  Maybe that's just me; I find millepiedes repulsive while not being especially bothered by moths, spiders, or crabs.  To each their own.

Great thread idea.

ditto  8)