Hello, Cappy! I use a combination, depending on the situation - with the shelter dogs, we have standard visual cues we use as part of the program there with which I'm involved, which are closer to, or sometimes are - the trad. hand signals found in trad. obedience. Since this a shelter-run program I'm involved in, things are standardized to a great degree. As far as I know, all the dogs adopted through this specific volunteer program I'm in <the dogs of which are a subset of the overall shelter dogs available for adoption> have gone to homes with hearing families. I'm hoping that if we had a Deaf family adopt one of the dogs, we'd get a terp in and start working on the ASL signs the adopter wanted to use in the home.
We also use the "thumbs up" common overall for deaf dogs.
With my own dogs I use a combination and if I had a Deaf client personally I lean toward some ASL signs and some classic dog training cues such as the trad. hand sweeping motion for the recall - but would do what the client would like.