Good quick fix. Not knocking your idea. But, I would prefer to get something more ruggedised for piece of mind. I've had mast clips fail. It's not nice to the mast when they do, and then wonder why sail is not behaving itself during session. Good reminder for me to check mine. Long over due.
veryseal.com/product/34-5x3-55mm-nbr-buna-n-70-duro-o-ring/ 
