As others have noted, the "ceramic" content of these spray sealants is so miniscule that you won't have a problem if the towels are properly laundered. This is in contrast to proper resin delivered ceramic coatings, which cure and harden within the fibers, rendering the towel unusable.
"Proper" laundering involves the following -
- Wash towels IMMEDIATELY after a detailing session. As in, don't toss them in a bucket and forget about them for a week, a sure fire way to ruin a towel.
- If you can't do them within an hour or two of use, put the towels in a bucket of water until you can.
- As I work, used towels are put into a bucket with a lid on. This is not intended as a long term thing, it just prevents the towels drying out while you are still working. Mike Phillips calls this a "clean, dirty bucket".
- Use a dedicated detergent. This is not marketing bull, these detergents are designed to remove modern sealants and polish residue effectively, prolonging the life of the towel. I often read of people saying "why not just use normal XYZ detergent, its cheaper". But then somehow, they are worried about ruining their "good/expensive" towels with sealants. That's contradictory.
- I use Rags To Riches, but the following are also good options too -
Micro-Restore
Bowden’s Own Microfiber Wash (AUS)
3D Towel Kleen
Poorboys Typhoon
Gyeon Q2M Towel Wash
McKees 37 Microfiber Cleaner/Rejuvenator
Chemical Guys Microfiber Wash
Carpro MFX