The Dominion may not call off the war, but it would give Starfleet and the Klingons time to build more ships, train more men, study what Dominion tech they have and watch the Dominion crawls through space to the fight.
Where ever the Dominion goes Starfleet and the Klingons would be there waiting. Strategically placed ships would be able to respond to a Dominion fleets weeks before the fleet got to the exit point they chose. As a tactic, when a Dominion fleet get's near the edge of the distortion, Warp speed strafing runs could be conducted. Firing torpedoes at the Dominion fleet as it neared the edge of the effected space. Torpedoes moving at high sub light speeds should prove to be a problem to the ships inside the effected area.
I will grant that it would be a major escalation in the war. But the Federation and Klingons were losing. As was mentioned before, if you're losing to an enemy that think your kind of life forms (solids) are inferior and the lives of these inferiors are no more than an infestation that should be wiped out; wouldn't dusting off everything you know you can do be the only choice. Genesis, a Soliton wave, biogenic weapons, the Omegas Molecule shouldn't all those at least be on the table? Hell maybe even take that captured Jem'Hadar ship and if possible, find the nearest Borg ship and lead it to Cardassia. Ask Kevin Uxbridge if he'd just send the Dominion fleets and founders back to their side of the Wormhole should be a plan too. Not kill them, just send them back.
Okay, that was a rant. My apologies. But if it slows down your enemy, and you can map the effected areas so you can still warp around space, wouldn't it be in your best interest to do so?