I use a standard Park chain tool to push out the Campy pin in my Chorus chains, and then use SRAM, or KMC or whatever brand of link I have. You only need the missing link tool for opening it back up (and even at that you can get by without it). If you dont have the tool and want to lock the link, just lock the back brake and stomp on the pedals - it's better to push a bit by hand first to make sure it's seated correctly.
My 1st gen Chorus monoplanars, still dirty after 25 years on the Montello, and the very pretty Deltas that I'm scared to use.
