I’ve seen $20 per room advertised. Really I think it depends on the quality of work and how generous/penny-pinching you want to be. I’d say $20/hr is extremely generous, $10/hr may not be worth their while and you may get a lot of “sick days” and shoddy work. Surface cleaning probably isn’t as valuable as stuff like windows and oven cleaning, and if they really get behind appliances, etc.
I also imagine like most entrepreneurs, cleaners would generally prefer more work than less.
Also, as others have pointed out, I do strongly urge those who hire cleaners to hire those who can work here legally. Employers create the demand that fuels the illegal immigration problem. Especially in an environment like this, there should be plenty of legal immigrants and citizens willing to work that hiring illegals isn’t necessary.