I don't know anything about IDPA, but we were familiarized with techniques for one-handed reloads of pistols - stick empty gun with slide locked back upside down between the knees, insert mag, remove from between the knees, drop slide, fire. We never practiced it formally at qualification (disaster waiting it happen), but were encouraged to practice it on our own. I did, and it is surprising how quickly it can be accomplished.
I suppose the same technique would work with a revolver, given enough barrel length. There may be other techniques but I haven't ever looked into them since I prefer to have a gun for each hand.
Safe, especially in a crowded range setting? No, but if it becomes necessary in a SD situation you are in a tight spot and you may as well be acquainted with it....preferably by practicing with dummy cartridges.