My question to the OP, why do you want to ground the revolver instead of returning to holster? Are you trying to gain a competitive advantage? Is there some other issue? Is their a safety concern?
I have participated in the sport since 2000, written many stages and helped put on many matches as an officer and volunteer. I think this, in my humble opinion, a question that skirts the "Spirit of the Game" to some extent. I have shot in virtually every category and now shoot Gunfighter. I have had two stage DQ's due to revolvers not being returned to holster properly and they fell to the ground, one of those was a State Championship. Drawing from and returning to holster is part of the game, it's spirit, some may say, think of all the movies, TV shows, books we have consumed growing up. The hero and villain alike never just set their pistol down after shooting it (unless called for in the script). In writing stages, I have had people start with pistols staged with the option to re-stage or re-holster, shooter preference, in most cases I believe the intent is to draw from and return to leather unless stated otherwise in the instructions. The exception of course would be due to malfunction and if a safety issue arises.
I have also had new shooters ask to stage pistols when they did not have leather yet or when their rig broke, I have accommodated and recommend that when it has occurred, keeping in mind this is just a game. If the stage instructions are not specific, you should ask if something is allowed during the reading of the instructions. Many stage writers make assumptions based on their experience in the sport, assumptions made on what the game calls for, or perhaps belief that we all see things in a similar way. It comes down to what is the intent of the stage instructions to keep the competition the same for all participants and most importantly, is it SAFE!