I don't have a better suggestion, but I have a BUTTER suggestion (that was pretty bad, I know...). Try pro-cure trout butter. That's the standard trout plug scent. I've heard they don't really use trout, but now I'm seeing some of it's labelled "rainbow trout butter" and they state on the container that it's comprised of ground up planter trout (finally a use for those things). Give that a shot. I've used it before and haven't noticed a considerable difference, but let us know how it goes.
-Brian