LOL Patti, those chins sure don't hide how they feel do they?
One of my chins was fed only oat hay when I got him and so he had a big bag of it when he came to me, I started giving him timothy daily and gave the oat hay to everybody occasionally. None of my chins cared for it much, not even the one who it came with (it was really dry though, a fresh bag might have gone over better). I do have to say though, he came to me very healthy. Oxbow sells oat grass hay
along with thier other chinchilla hays, and chinworld also sells it, so I wouldn't worry about the safety of it. I personally would use it as more of an occasional thing than a daily/main food. I bet Jorgha could tell us more about it.