Shower hygiene

We use the GS Travel Directory and look for locations with a good rating in the middle category, restrooms and showers. A star after the rating indicates a clean facility; it may be old but its clean. It has worked for us. We've stayed at a few places with a high number and without the star and still found a good facility. Even if not as clean as one might like, the chance of contracting a disease while wearing suitable shower shoes is very unlikely.

I believe you are more likely to contract food poisoning at a restaurant than you are to get a disease from a shower. (Can't back that up; just an opinion).