well you can try some fo the formax belt grease that pop's knife supply carries
its supposedto help the belt cut better. from what i hear its good to use on old 400 grit belt and they polish like a 600 grit and 600 grit will polish like an 800 grit, someone chime in hear and correct me if i'm wrong please, but the main advantage like any machining lubricant it seems is faster cleaner cutting.
let see what the experts say