Saving a client money in this manner is not in your best interest. He OD a horse one day. The next day there was a warrent out for his arrest for using a controled drug on a clients horses. Last I heard the guy was in jail in another state for some stunt. Practicing veternary medicine without a license is also a crime.
Trainers do both.
The effects allow the horse to learn while doped up. At times owners have tried Ropom and Ace, but I have found it is to dangrous to use. Had a vet last week that was still using the ace ropom mix. I ask him about Dormosedan and suggest that he use it next time. If you have a problem, you will be in big trouble with no defense.