we dont use bottles, but I stopped with all teh utensils around 6 months. He's had no ill effects. I decided that it was a bit of a waste of time seeing as he puts his hands down everywhere and sucks his fingers etc. Virtually any item he comes across can end up in his mouth.
Someone here told me that it's just the bottles for milk that need steralising after a while as there is a partic bacteria which is in the milk.
.....when she was a little baby and I wouldnt even let her have her dummy if it had touched the table ... now it just goes in my mouth!!