If water will clean it, just use water. If not, break out the suds. No reason to call anyone an idiot. Just use common sense. Sodiom hydroxide is not good for aluminum, it melts it. If you can get a coil clean without it, it's better for the piece of equipment.

 

I find that if a coil has been cleaned the year before, I can sometimes do it with just water. Between pollen and pollution, I don't often find that in this area.

 

Coil cleaner to be sure, especially indoor coils. how else can you disarm air born particulars......like the swine flu, not to mention the bird flu and the black plague!