I usually use a blow off tube for the first week or so or when I actually remember to throw an airlock on it. My blow off tubes are relatively small as I use a 3/8" tube with a cutoff ball point pen housing. Fits perfectly in the stopper hole, easily changed out and yes it seems small, but have had no blow outs in the 5+ years of brewing.
And back to more of the point, like bennie mentioned, I am gonna need it for another brew coming up! Never had any issues with stuff falling back into the brew either.