Sure. Just make sure you have a gallon of white ceiling paint handy.
Seriously though, it depends on the beer. With a wheat or some high-gravity beer you're almost guaranteed a blowoff. Even a modest pale ale can can easily exceed that one gallon of head space. Why take the chance? Just use a blowoff untill the krausen starts to fall, then replace with an airlock.
For my blowoff I use a standard 3 piece airlock with the tapered bottom trimmed off (so the gunk can get through) and run a length of tubing from the top of the airlock. (It's either 1/2 in ID or 3/8 in ID, I can't recall.) When the blowoff is done I pull that airlock off and put a fresh one in, no need to remove the stopper.