Wash your towels in hot water with a cup of vinegar, then run again in hot water with a half-cup of baking soda. That will strip your towels from all of that residue & mildew smell & will actually leave them feeling fluffy & smelling fresh. Going to do this with the washcloths and spill rags.
Unblock your drains without pouring harmful pollutants into the water system by pouring down 1 c of salt and 1/2 c of baking soda mixed together, followed by a kettle of boiling water. Can also use baking soda and white vinegar and boiling water. Much cheaper than draino!