I've never seen it done either except on TV. I was just thinking about "How do you get rid of unwanted critters" and it popped into my mind.
The internet answers all things. It looks like the main bug which fumigation tents kill are drywood termites which live inside the house. Around here the termites are all subterranean so they live underground and commute into your house to eat. Thus local treatment is to either pump in a poison barrier around the foundation (something nearly every house around here has had done) or the more recent method of baiting and poisoning the nest. Separate the underground nests from the house and the worker termites inside won't stay for long.
I guess California has drywood termites living inside of houses so that's why it shows up on TV, like the "Chicago" palm trees in National Lampoon's Vacation.