I had a clogged drain pipe (coil to pan, not pan to outside) due to a bit of algae. It looks pretty clean now, but I'd like to clean the drain tract on the coil to knock down the trace amounts of it so it doesn't grow.
Home depot said they only have the pills for the pan and nothing I could spray on it...the guy that was helping me seemed a bit clueless though.
I don't want to use bleach as I heard horror stories of it ruining the coil when people didn't get all of it rinsed.
I am going to try and vacuum the small amounts of debris off the return side of the coil as well, but I am not sure if I can access it without major disassembly of the duct work.