Used to roll my eyes at grout bags honestly. Figured they were one of those tools old timers push on you just because that's how they always did it. Then I tried one on a curved arch last summer and wow, night and day difference. The grout actually goes where you want it instead of half of it ending up on the floor. Took me way less time to clean up too, which I never saw coming. Guess sometimes the old school way is old school for a reason.