I remember someone asking about blowing the air lock off their carboy during primary fermentation. I took a .5 tube and plugged it right into the air lock. The open end goes into a bottle 1/2 full of water to act as a large over flow for the blow off. Here is a picture of the final product.
I do the same, but I run the hose into a growler filled with iodophor sanitizer solution.
I use the same setup but no sanitizer, just water.