Each state in the US has its own regulations on pesticide use and licensing - any time you make a commercial kill claim against an insect or other pest, or even apply a chemical that is labeled for use as a pesticide but in a non-pesticidal application (like Microban X-590, which is an antimicrobial but also has pyrethrins in it), you must abide by both Federal regulations on useage, and by your state's laws on kill claims.
I get a lot of guys whose customers have asked them to get rid of bedbugs, fleas, dust mites, etc, and I always refer them back to these laws. The way I put it is, if your customer needs an exterminator, have them call one. I wouldn't ask my dentist to do my brain surgery, just because his hourly rate is lower, so your customers ought not expect you to perform the job of another company either.
MasterBlend's Repel doesn't count as a pesticide because it makes no kill claims - it just shuts the front door of the restaurant so the little boogers can't eat.
Crazy but true - if a customer decides to go get an Adams flea bomb at PetSmart and set it off in the house, that's private use and is essentially unregulated. But if you as a cleaner accept payment for setting off that exact same flea bomb they bought at PetSmart for them, you must be licensed.