Trevor,
To expand a little, just remember as Brian said, try to describe it as a general cleaning. Last time I went to the dentist for a general cleaning, if they would have found cavities, needed to pull a tooth, or had to do a root canal, I guarantee I would have been charged extra. Likewise, I took my van in to the shop not long ago to get a “tuneup”. Do you really want to ask me what else they found that wasn’t included in the “tuneup” price? Ouch. If other cleaners want to give a price that includes “everything” when it comes to spots, let them. I want to give each spot the time it deserves if the customer is willing to pay for it……or I can give the response many of the other cleaners will give “that spot won’t come out” so they don’t have to eat any additional costs. If you are hesistant, shop your competition if you haven’t already and look for the areas that you can charge extra for if that’s what you market is dictating.