I can only confirm from my countless stays: Towels are indeed a reason for additional charges to the bill.

As part of my job I regularly support my company's site engineers, when installing equipment into Chinese steel plants. Quite some dust around there.
After a days work it's the "post shower towel cleaning" that does the trick.

Eventhough the towels will be perfectly clean after machine washing, hotels more often than not try to charge for "towel replacement fee". Asking to show or give the dirty towel usually makes the fee dissapear from the bill.

What type of hotel offers this "service?"

I've found that there's nothing miscible about the water droplets and towels in budget Chinese hotels. Not to mention they shed quite a bit...though I've never had an issue at the front desk. By two biggest problems with many properties in China are thin walls, and waiting for some clerk to check the room out. There's an uncommon occurrence that the deposit is way too much vis-a-vis the quality of the hotel (say �‎800 for a �‎250 room for one night), then again they have always paid me back in legit bills too.

I was staying in a place in Liaobu, Dongguan (if you'd like a recommendation, there's a nice Korean restaurant nearby), and wanted to stay for a few nights, but because the scanner wasn't working (for my passport), they told me to leave after one night. Why can't they just do it at a store? Anyway, the proprietor felt bad and did my laundry.

I heard from a hotel guy regarding the rigorous requirement of deposit ，according to him
they are frustrated every now and then with some random occurrences such as where towels had been badly smudged and unsalvageable (some guys use it rug shoes) though he admitted that most guests are really decent, but they could not come up with different standards when treating clients and they are unable to identify the potential people so they are forced to approach a way too much(like check room when checking out) particularly in less profitable budget hotel
I think it is apprehensible and you guys cleared my mind with ease in cc safe regard
so I'd comfortably comply it
and do you also think the reason is making sense for you
maybe in some upscale hotels they should take unintentional minor damage as kind of costs and just waive it
Thanks all

What ever hotel is available in the city we work in. Ranges from Holiday Inn/ Crown Plaza to local 4/5 star hotels.

In my experience it's more the size of the city that matters. Smaller town hotels tend to have little interest to accomodate our western expectations. Simply because westeners are an unimportant group of guests. Local companies/ governement officials is what makes them tick!

So in small towns, also HI/CP staff will make you wait at check-out for checking ur room or add the mentioned towel fees.

Important thing is to keep smiling and wait for them to do their job and get rid of the fees