We got our trashcans full and immediately salted it like mad the whole inrun. The jump lasted till we were ready to leave and we never needed more snow due to meltage. Im in DC so its like 40 degrees or higher.
something that works better than salt is fertilizer. its what they use in racing when its higher than freezing outside so that they don't make huge ruts in the hill. try fertilizer next time it'll work wonders.
it does in mass, but not if u put a little bit on. (it will melt a layer, then the layer will freeze over - hardening the jump or w/e) but don't bother with salt use fertilizer!