I didn't by that technobabble about following identical trajectories to move through time in your own universe, and the elaborate plot to hide time tampering until the last second didn't make sense/was wishful thinking (it's still an alternate reality in which the bombs exist, whether they're found or not. By default there's one timeline where you set the bombs and one where you didn't).
Yeah, but the point was not to eradicate that alternate timeline, it was to make sure they didn't alter/cancel out their own timeline in the process of saving the universe. It actually works out pretty well and avoids the usual time-travel cliches. (There's actually a bit in DTI: Watching the Clock
where Lucsly reflects on how good a job the DS9 crew did of respecting the Temporal Prime Directive during those events.)