They are supposed to do a hand check if you request it. But the experience of most people is that film slower than 800 is fine in the carry-on scanners. The only time recently that I've requested a hand check was leaving LA a few months ago with about 20 rolls of freshly purchased film. They weren't busy, and they did the check with no complaints, it took probably 5 minutes or so. I think they swabbed each roll, but they didn't remove any from the sealed boxes or inner wrappers. I did my part by having that film separate in it's own ziplock bag so I could just hand it to them. I sent a couple single single rolls through the scanner with the camera on that trip.
Other than that, the camera and film go through the scanner and I've noticed no ill effects.
I've done the "stuff a 120 roll" in your pocket trick a couple of times, however, on my recent trips they are asking specifically if you have anything in your pockets.
Another aspect is that it's too much trouble to ask for the hand check without a good reason, IMHO anyway. I always travel with a laptop, which has to come out of its case. Your shoes must come off, if you carry liquids, those must be separate, and now it's coat season (which also comes off), then there's the camera case, not to mention possibly a suitcase . Managing all the stuff and keeping track of it without holding things up, and asking for a hand-check of film is too much. YMMV.