When did you stop sterilising bottles?

At 4.5 months I stopped because mine were all going in the dishwasher and I usually give them a quick rinse before I put them in so that the milk doesn't sit in the bottle. Also he was on the floor a lot nibbling everything he could get his hands on. Stopped now as we are weaning. I inspect all the bottles for formula residue esp the lids if it has been shaken.

If you’re giving formula, bottles should be sterilised until 12 months more so to keep the actual formula sterile x

As above, the reason for sterilising is because formula can contain bacteria