[DRJDVM's '69]

One technique that has worked for some of my clients....

Fill the hole with a bunch of his own dog crap....yes that dog crap.... and then bury it....the **** needs to be near the surface....maybe a couple of inches deep at best....

Worked pretty good with my mastiff...but he wasnt an obsessed digger...just an amateur...

Coffee grounds work pretty good for cats that dig in flower beds...not sure if it would help with a dog...