No Blow-off... what now?

My third batch, a 5 gal American Wheat, is fermenting in a 6 gallon better bottle (brewed last night, it just started really going late this afternoon.) My lowest gravity beer yet and its filling up my airlock. I've got a spare airlock and I sanitized it and switched it out when I noticed it starting to fill with crud. I have no tubing to use as a blow-off and I can't get out to get some until tomorrow at the earliest. I don't really want to be cleaning the ceiling of my beer cave in the morning.

Should I just keep working the airlock switcheroo strategy or is there a better alternative?

If not, Is there any reasonable assumption as to how frequently I should do this or how long it might last?

Just take out the airlock, the active yeast will protect the beer from any containments with a layer of co2. I had to do this when a belgian was fermenting very vigorously. This isnt ideal and you should pick up a tube for a blow off since it will happen again with another beer.

If it is really that vigorous, I would let it open air ferment for 24 hours. (put some towels around it and let the krausen boil over. Best you could probably do. You wont have to worry about oxidation with all of the CO2 produced