Any spray paint. I use rattle cans from Walmart. Technically, the foam is sticking to the paint so the adhesion is remarkable.
BTW, the method I describe to stretch out the Silicone and make it more affordable may require you to cover your model more than once if you're not totally covering it. You want the "Good Stuff" to encapsulate the lure, totally. The thinnest of coating will suffice.
Another thing you can do is make "Filler" pieces, pebble sized from the cheaper silicone and put them in the mold box after you make your initial coat and it cures. Put some good stuff in so the pebbles will have something to grab on to, add the "pebbles", and then use the good stuff to cement it all together. You may only use an ounce where you would have used 4. Once it sets up, it'll be a pure silicone block.
Try a test piece to assure compatibility. Usually, the cheaper stuff will stick well to anything so I'd be more concerned with the Molding Silicone if you're going to use the filler method. Good Luck.
Mike P