Some folks will just wash with clean water and add straight to the fermented beer. The alcohol will protect the beer from any spoiling organisms. However, fruit may have some wild yeast and if not pasteurized may start a secondary fermentation which could last months, and leave some different flavors.
I like to pasteurize fruit. Place in some water and heat to 160 F and maintain temperature until heated thru (5 seconds at 160 F will pasteurize, but solids (fruit) will take longer to fully get to temperature). Don't heat too high or you will set pectins (haze in the beer).