We do DS's teeth only once a day in the bath. I think at this stage it is more about learning good dental habits and getting used to have them done iykwim? I was told that doing it with a face washer is fine, but I got this great set of baby toothbrushes that have one for each stage of the first 12 months, the first two have rubber heads and it is only the last one that has bristles.. I just got them from the chemist, they were pigeon brand from memory.