I would first look at the weight of your hooks, are you using heavy wire hooks? Second what other materials are you using? Bucktail is way more buoyant than say marabou. What about chenille, are you using standard chenille or ice chenille? I've never had a problem w/ gurglers getting water logged, I use craft foam almost exclusively, I don't think that coating the foam would gain you much, maybe using more of it might help.