Preparing fruit for beer.

I was planning on adding some peaches to a saison I just brewed and was wondering what is the best way to kill any wild yeast or bacteria in the fruit. I was told by midwest supplies that freezing will not kill it all and to add potassium metasulphites to take care of it all. Does anyone have experience doing this? How much do i need to add for say each pound of fruit? and should i freeze them also?

 

If your looking for a really simple no fail way to sterilize your fruit, you can mush it up/puree it then add vodka and let sit for a few minutes. If you weren't using peach, I would just soak the fruit whole in the liquor then crush.