Method works, but comes with certain risk like causing damage or death to the fish. (Not all fish that are sold are 100% strong and healthy). Put the focus on containing them in an ammonia free and oxygen high environment right now.
To cycle the tank without risk, best proven method is to just drop in a source for ammonia, sit back and relax. (Maybe if you have to start another tank, think about this method :) )
If temp is 78 and salinity is 1.025. Those params are fine, I would personally lower temp to 76. This slows down metabolism fo possible pathogens and helps the water to contain more 02. Do this gradually as stability is also key to the survival of your clowns now.