Hi mike
I have a mattress to clean at one o'clock said the same as you did,stains are hard to remove as they are nearly always cotton based material,I use a prespray that kills dust mites as well up sold the sanitizing side of the clean not the stain removal aspect,and she was happy to go ahead, will be using my magma heater on the steam setting to help with the dry time.
You still busy I hope,I have been quiet this last week or so
Oliver Collins