I find what works well is an alloy side entry clam cleat, with a small nylon horn cleat about 4″ above it.
When hoisting the sail you can pull it most of the way up directly from the sheave at the mast foot, then when it is nearly all the way you can hook it into the clam cleat and bowse it the rest of the way with the cleat holding it firm.
Then when you’ve got it all the way a couple of quick figure of eights round the nylon cleat secures it once and for all, whilst at the same time taking the load off the alloy cleat so’s it doesn’t damage the rope as much.
This method is simple, secure, and easy to undo again in a hurry. I wouldn’t trust a cam cleat not to slip at some point, usually when you least want it!