Lens manufacturers say that anything other than a microfiber cloth will damage the coatings on a lens. But microfiber cloths eventually pick up crap and they look like they’re a pain to wash.
How do you keep your lenses clean? Are you using cloth/kleenex or microfiber cloths? If you use microfiber cloths, how do you clean those?
I use warm (not hot) water under pressure. Dry with a clean hand towel. Warning: don’t use towels that were fabric softened, fabric softener can leave some nasty, hard-to-remove streaks on the lenses.