I had pretty good luck using a Holiday Inn Express self-serve laundromat the last time. Well, except for the red t-shirt that I bought in China that turned my underwear pink -- a lesson learned! It was definitely easier than the laundry alternatives I've used before in China.
This time, it looks like I'll be in Chengdu during the middle of my trip and I see there's a well regarded and very affordable HI Express. I guess I'll have to trade some "luxury" and frequent stay benefits that I could get at other hotels for the ability to do my laundry.

ButI've found the free HI Express breakfasts to be decent in China and the rooms more than reasonable, so it's hardly a hardship.