I think every day is a little too often. I only wash and sterlize our dummies when they've hit the floor too often... Probably once a week or so. I figure as soon as I take them out of the sterilizer they are not sterile anyway so what's the point.

Mitchell licks the floor... I can't sterlize that, as well as every toy, hand, bib, sock and whatever else goes into his mouth at the moment.

Also I think that 10 minute for boiling is too long. I always thought 5 mins was enough for bottles so assume that it is the same for dummies too.

But all of the above is just me. If you notice a teat deteriorating then I'd bin it.