Engineer on a ship we service makes his own from this recipe:http://mad-science.wonderhowto.com/h...juice-0134730/

Myself, I use sulphur sticks for tiny hard to find leaks http://en.wikipedia.org/wiki/Sulfur_sticks downside is you have to wear a gas mask when using them, and if there is a lot of ammonia in the air you just fog up the room with white smoke.