I run my bottles through the dishwater with the hi-temp wash and heated dry cycle. Have also done the same with corks. Then I soak the bottles and corks in a solution of Metabisulphite and water before bottling, but this is more for residual oxygen scavenging. This is what I have done, but..... a month or two ago there was a thread addressing the issue. I don't remember the title, although you could do a search. I do remember Yooper contributed to it, and she said that you really don't want to get the corks wet before inserting (if I remember correctly). And the consensus was to not run the corks through the dishwasher. I'm going to look for the thread before my next bottling session.