Teething pain is a complete myth. Your child is teething for about 3 years (seriously, teeth are constantly moving through the gums for years). In that time they will be grumpy, chew on things, get rashes. Blaming it all on teething is convenient but without any evidence. Stick something in the kid's mouth, maybe they get distracted, maybe there is confirmation bias on the mothers part, maybe people just make associations where none exist. The fact is they do nothing a plastic chew toy doesn't do but with far higher risks.