TheBroonery, that may work too, but from my testing with the sacrificial carboy, Plasti-Dip is what I use. Of course, they are rarely used now that I ferment in Sanke kegs.
One thing that I recommend is, DON"T use hot water. The thermal stresses alone on the glass when filling could be enough to break it. If you're near it when it breaks, you could be injured, and God forbid, if it breaks when you're handling it, you'll be in the same boat I was... am. (Still have no feeling in my index finger, but the middle finger and thumb are slowly getting feeling.)
When your beer is done fermenting, use luke warm water and Oxy-Clean or PBW, and let it soak overnight. You can use the bleach for sanitizing, but I'd use a low concentration. 1 tbs per gallon of water is what I used to use.