Olive oil works great for shackles, traveler tracks, and blocks. I've been shocked by how long it lasts. I'm sure a cheaper or lighter vegetable oil would work all right too, but I don't use those much for cooking so I don't have them around. Triflow, lithium grease, etc work fine too, I'm sure.
Sailing a '74 Challenger 40' Ketch rig out of San Francisco