Dry suit testing and maintenance

This weekend, Jesper and I recieved two brand-new Kokatat Expedition drysuits for the trip, and had the first chance to try them out in the surf. The overall impression is really good, the quality and the attention to detail that went into them are amazing. One thing we discovered was the importance of greasing up the metal zippers - without some sort of lubrication, they simply get stuck which (as Jesper can probably testify) isn't ideal when you're wearing the suit and need to get it off.

Judging from this weekend's experiences, my guess is that the zippers need maintenance at least once or twice week when the suit is used on a daily basis. I went to the local diver's store and bought a stick of zipper grease, which seems to work really well. But what if you're stranded somewhere without that sort of stuff? What else works, and are there some substances to be avoided?