By “oxiclean” I mean sodium percarbonate. I buy the store brand instead of the OxyClean™ one. You could also use washing soda (sodium carbonate) with almost as good effect. Boosters like that keeps you from using too much laundry detergent that leaves a residue, which might not be nice on a towel you dry your dishes with. Although I view such residues as merely annoying and harmless in the small quantities you’re likely to ingest. Chlorine bleach obviously can help whiten stains and provide some sanitizing abilities, but it can be harsh on natural fibers like cotton towels.