Question: I have a 19 liter carboy, and put a 18 liter wort. 10 hours later I woke up and noticed carboy overflow krausen all over it.

I am concerned whether air lock will clogged down and explode. I will not have a hose for another 6-7 hours, so blow-off tube is not an answer. I cleaned the air lock a few times, and it keeps overflowing, I see krausen in the airlock.

I am wondering what could be a solution? I am either thinking removing air lock completely for next 10 hours, or siphoning some of the wort to give some head space.

Answer: 
Few tricks for temporary fix.

Swirling every so often can get kausen to drop back in.

Nitrile glove with a pin hole in a finger will work for a DYI air relief cover, should limit the mess. Latex will work too but not recommended due to their odor.
You could remove the cap and tape a piece of foil or plastic wrap partially over the opening. I’ve done this with Saisons to prevent back pressure stalling fermentation.