Personally I have not ever had this happen, but I agree with others that things I thought had gone missing turned up in the strangest places, and people seem to rush out at the end leaving all sorts of things behind, so we often have to give them the benefit of the doubt. I have had glassware disappear, and one never knows if they were pilfered or broken, it just becomes a cost of renting. It’s a learning process! I have also learned to supply very generic towels - good quality, but very uninteresting. No point in tempting folks with souvenirs. Along those same lines, I buy all white towels which are easy to mix and match. When I first began renting, I had lovely jacard light blue towels with a detailed trim, and when a few became permanently soiled, that was the end of the entire set. Since then, life has been easier and I replace soiled face cloths every year with new ones. I also provide towels specifically for makeup. Doesn’t help the pillowcases, but has made a difference with facecloths.
