One nice solution is to have a second stopper/airlock setup. After the big "boil" has settled down a bit.. star san around the first stopper.. star san the new setup completely.. and just replace. You still have a ton of CO2 being created.. so, no issues with O2 getting in.
And, even if you go with Revvy's solution, which is better, you still have a spare in case you break something removing the blowoff tube.
Hop Song Brewing