When my dogs were kibble fed, I always offered them recreational bones for gnawing without any problems (besides the occasional runny poop if they had too much marrow from femur bones). If it works for Guinness, then keep it up.
By the way, just to let you know that you can most likely get femur and knee bones for next to nothing at a butcher's instead of the pet food store.
"Education is a progressive discovery of our own ignorance." -Will Durant