Pretty funny to me, reading the responses from those that have obviously never tried tying in a swivel above the float.
Takes about 3 minutes, and give it a try. I change my mainline halfway through the fall season, because of the stresses it receives from being stretched from fish. I could probably use it the whole season, but line is cheap and I hate wasting the 15 minutes to retie, when the fish are "on", due to my laziness.
Or you can keep replacing line, and dealing with the frustrations of line wrapping around the tip, etc, etc,