Care and cleaning of your grips is simple. All that needs to be done is to wipe them down with a damp, lightly soapy cloth to clean any dirt off of them. Waxing and oiling are not necessary due to the finishing processed used.
If you do wish to recondition them due to extended exposure to the elements, I recommend using Birchwood Casey Gun Stock Wax. I use True-Oil for the finish and then their Gun Stock Wax as the final surface coat.