I have never used a safeword with my Master. However, I do have one in case I ever truly need to. As for holding things... I don't think that would work for me, I tend to forget I even have hands. lol The safeword my Master and I have choose is perfect. It's not something I would ever say in day to day conversation, but I most certainly won't forget it. And since neither of us enjoy gags, there is no need for nonverbal signals.

But, fetishdj did have some good ideas if I ever needed to use any.