I never put more than one in the vibrating tumbler. I read through a really old thread before I tried it. It said fairly clearly in the old thread that putting more than one in the tumbler at a time would cause chipping. I'm not sure where you read it was Ok to do so. Sometimes you have to consider who gives the advice at the same time. There are thousands of members here and everyone can voice their opinion. You need to weigh who's opinion you are accepting.