Leave it alone to do it's thing. If you're using a 5 gallon barrel there's plenty of surface area. If it's freshly dumped like mine were you'll only need 10 days to two weeks for there to be noticeable flavor from the whiskey and the oak. Plus rocking after fermentation will introduce more oxygen on top of having to transfer from your fermenter to the barrel and from the barrel to a bottling bucket or a keg.