Tiller tamer and ratchet block?

My Super Porpoise requires that both hand be kept busy, and some times I could use a third. It doesn't have a place to cleat the mainsheet, so I have to hold on to it all the time. I also have to hold the tiller to maintain course. Every once in a while I'd like to let go of either one, usually the sheet, to do things like pick up my water bottle and have a drink. Important when it's hot and sunny. Or just to relax my hands when they cramp. Or to wave at another sailor
I was thinking...

Tiller tamer and ratchet block?