I use CCM regular plastic; and while they will float if you drop them in the water or a fish throws them off the hook, the 4/0 hook I use to rig them is enough to sink them. I don't use foam or balloons personally. If I have a follow and pause and let it slowly sink, that often triggers a hit. Balloons are probably more convenient because you mix them into plastic. You should wear a respirator anyway when dealing with hot plastic, so lung irritation should be a non issue.