I didn't use bottles at all with Emma but all accessories - sippies, straw cups, dummies etc - I washed on the 90 deg cycle in the dishwasher.
With Oscar, I had a lot to wash and sterilies post-4 mths when I went back to work - two sets of pump equipment per day and bottles - and I did the same thing. But I *think* I finished sterilising a good bit earlier than a year both times. Could the recommendations have been a lot younger back then?
Anyway, I think at a year old, the high cycle in dishwasher is enough....
But that's me.
S x