No, I've not heard of that before either. When BB had her extractions a few months back, she also had quite a big hole where one particular tooth was rotten and they'd had to clear some neighbouring tissue - but there was never any mention of poking around with a cotton bud! She had antibiotics to deal with any infection and although there was a bit of blood the next day, the mouth healed quite quickly, I think it was about a week later when we went back and the gums were nice and pink and the hole was healing nicely.