You're absolutely right about salmonella; I have to be meticulously careful about not spreading it. I religiously clean my hands and arms so much that I should buy stock in soap and hand sanitizer.
All my herps are housed in the living room, and I take care to ensure that surfaces are clean and sanitary, since the fids and other pets do visit that room.
My lizards and python are handled and let out to roam regularly, which means I'm cleaning pretty much constantly. When Panzer was climbing on my sofa (and me) last night, I had blankets spread over the entire surface so he didn't make contact with the cushions, then when he went back to his terrarium, I put all the blankets in the wash on the sterilise cycle, changed my clothes, then sprayed the sofa with F10 and wiped down the floor before hopping in the shower. It's the same routine every time a herp comes out to play.
Overkill? Maybe. But having 13 pets makes you kinda nuts anyway.