Question: can you boil a bamboo toothbrush?
Answer: If you can reuse your worn-out toothbrush before you compost it, so much the better. I've cleaned an old one (by boiling it for 3 - 5 minutes) and used it to clean grout in my shower, to gently scrub a stain out of clothing, to smooth melted beeswax over fabric to make homemade beeswax food wraps.