When you ask dad to just practice on a mat in the backyard, does he counter with "it doesn't feel like the real thing?" The maybe you should get him the Glide Pad from SKLZ
($100). With a sliding surface, the Glide Pad moves forward when you make contact, offering as close to the natural feedback you'll get from an artificial surface. And at only 10 by 19 inches and less than 10 pounds, it can be used outdoors or indoors, and with a tee.