In MK brothels and most WG walkup, the cleaner guy will come and pick up the towels on daily basis, usually early am, around 5 to 7am and picked up the dirty towels back to laundry shop.
Same for hotel reservation, the papa/mama will replenish the towels, also via laundy cleaning.
The only self washing I 've seen is from BBS in china, that if u fuck in their aparment. The tiny towels still smell and some with stain. That I would said is fucking dirty. I only used it to wipe my leg and max up to my thigh. I use my own tissue (wet/dry) to wipe my dick and ass. My another survival kit......
Sometime I just let my undie do the natural wiping and drying.
What bout hotel's towels? Same shit, well maybe they add some dettol and lots of softener.
I learned the following:
1) I will never send my clothes to the laundry, except for dry cleaning.
2) Dont use fuck joints' towel to wipe ur dick or anus.
but what;s to worry? You already take the risk dipping your dick into the pussy. If we are too concern with hygiene, stay home and dont go fuck around.