We do hose testing on supect areas when doing IR inspections quite often. It works great for us and we have found numerous leaks using a plain old garden hose with a nozzle on it.

I just found a leak at a roof to wall intersection the other day using a regular old garden hose. I know the astm is a better way and will eventually invest in the equipment, but have have had Very good results using a plain old garden hose.