@Allison371
We just went through about 10 bath sheets ($$$) that are all stained with benzoyl peroxide medication. It's an orange bleached out stain that is obviously even on white towels.
I have stitched a red line on the corner of these stained towels so I know which are already stained. If new ones pop up stained that are NOT stitched with red, I will know that it's a newly stained towel and will charge them. We folded up all of the stained ones and put them in a basket in a bedroom closet. We have added a little note on the back of the toilet that reads: "If you or anyone in your group uses skin products with benzoyl peroxide, please use the clean and folded towels in the closet of the bedroom".
We have not requested reimbursement from guests yet but will do so going forward. We note this in our house rules so they are aware of this when booking.