My partner and I have put holes in merino wool after a month of use. Merino is NOT abrasion resistant if you're active. We're trying out Nuyarn, a merino blend that claims more loft and abrasion resistance (should also be lighter weight).
For moisture management/warmth in colder weather, we're also checking out mesh baselayers [1] since merino does not dry quickly under multiple layers.
But if the bidet has done its job, then the towels aren't poopy. A lot cleaner than dealing with cloth baby diapers!
Buy plenty of towels and you can spread out the washing a lot more. We do a load every 3-4 weeks probably.