I wash weekly. My bathroom has a tendency towards dampness.

They stay around until they start fraying and then they go in the retired towels pile, for pets and spills and such, and once they are embarrassing to hang on my outside line i throw them out.

I’ll soak in vinegar water every so often to reduce the limescale that builds over time and that helps keep them fresher looking, but mostly that is a losing battle.

Pro tip: don’t use scent beads or softener products. They reduce absorbency (and they’re nasty chemicals that smell terrible but apparently I’m the only person who thinks that).