I think a personal interview/meeting is mandatory and you should discuss this topic with the person you are talking to. Myself, I'd be fine with the homeowner looking over my shoulder the entire time if that's what makes them comfortable.
I think that would be great. However if you are a professional cleaner, you should know what signs of bedbugs look like and inform the homeowners ASAP.
I wouldn't recommend that. Why try to add a chemical into the air when you are running a purifier to remove impurities? Spotlessly clean the room, use a HEPA vacuum and then run the air purifier. If you need to add a nice smell to the room, try boiling... more