They use it all the time for horses that way ......I have used it with some Furacin mixed in by the vet and it works great....Use plastic gloves to apply or you will have funny taste in your mouth ....
DMSO is used mainly as a driving agent. Freddy's post is right on. If you can get some liquid furacin to mix with it that works best. Take a somewhat stuff brush like a tooth brush and rub it in where it is swollen. Hocks are hard to wrap but if you can make some saran wrap stay on it it will help sweat the swelling out.