Airlock Bung?

[Airlock-Issue]

So I've already started a brew this morning and I just realized I don't have another airlock bung (ie adapter/cork) I've been brewing for only a short time and this is the first time I was going to have two going at once (one, with the airlock & bung I have in my secondary; todays to the primary) Both my primary & secondary are glass carboys.
Any quick hints? Could I just go to Home Depot and get a similarly sized cork? I think they may also have the black rubber plugs? I could drill a hole in one to make my own? Kinda doubtful the black rubber is food grade but does it need to be?
Any help's appreciated.

 

[Airlock-Issue]

Oh & there are three homebrew supply stores in my area. EVERY SINGLE ONE OF THEM IS CLOSED ON MONDAY. Which f-ing blows as it is my only regular day off.

 

[Seven]

You can loosely cover it with a piece of sanitized foil until you can get another bung/airlock.

 

[microbusbrewery]

I wouldn't use the black rubber stopper...they usually have a strong odor and you don't want that in your beer. I'd get some tubing with the OD the same size as your airlock hole. Insert one end into the airlock hole and the other into a container filled with sanitizer (e.g, a growler).

 

[ianw58]

+1 to the sanitized foil.

All you really need is a way to keep the bogies from falling in to the Carboy neck but not restrict CO2 from getting out.

 

[Airlock-Issue]

Thanks all for the help. I ended up finding a correctly sized cork at True Value Hardware & I just drilled an appropriately sized hole. Seems to be working fine.
Also, I confirmed: DO NOT USE THE BLACK PLUGS SOLD COMMONLY AT HARDWARE STORES. They contain sulfur.