Having done this type of work, I'm surprised at the lack of information given, as specifiers normally have pretty strict requirements in terms of ; -
method of cleaning to be used
type of product to be used
access times
frequency of cleans ( I know you mentioned emergency and one offs )
The work we have been involved in has always been carpet and hard floor cleaning / maintenance, the biggest problem being chewing gum removal, which is not a problem to do, but the time available / payment, meant the gum removal was never completed.
The entire U K only needs about 6 - 10 operators to cover 200 or so outlets.