One super cheap idea that might be worth considering: clear shrink tubing. You could put whole trays of them at a time in your oven, just make sure the tubing i

One super cheap idea that might be worth considering: clear shrink tubing. You could put whole trays of them at a time in your oven, just make sure the tubing is the right length and lined up right. You might even be able to get away with not cutting out a hole for the button, as it could be activated through the flexible tubing.