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 do either of your suggestions, or if your carboy fits in a bucket, just let it overflow through the airlock until the blowoff tube arrives.