No the O-rings were essential to prevent blowby. If the seal the o-rings provided was lost, then exhaust gasses could exit the rocket not via the nozzle. This w

No the O-rings were essential to prevent blowby. If the seal the o-rings provided was lost, then exhaust gasses could exit the rocket not via the nozzle. This would cause a cascading failure where the exhaust gasses would erode the structure of the booster and make the hole bigger until eventual failure. In the case of Challenger, the booster structure didn't fail completely due to blowby because the fuel tank exploded first. What you're thinking of is the fact that they used multiple O-rings to prevent blowby, but in reality only one was needed. Blowby appearing on the primary O-rings was ignored since the secondaries prevented catastrophic failure on earlier flights, but any blowby erosion on any O-ring should have been recognized as a dangerous anomaly. O-rings were the best way to seal this joint because they had a high ability to resist temperature and pressure, while remaining flexible. There's no "putty" that could be applied that would have worked better.