I use Sheree's recipe for bath bombs too. I've never had any problems with them growing or crumbling until I sent them to Kimberly in NY for the swap. Your balls look great. I wonder if just cutting back on the salt would help those that have problems with them exploding. I'm thinking that the salt may draw moisture. I know when we have salt for ice and snow left over in the garage, it draws a lot of moisture all around it. At the beginning of summer, I finally pitched the bag b/c I was tired of the water on the concrete around the bag. I also made 4 batches of bombs this weekend...OM&H, Pearberry, Lemongrass & Sage and Frosted Snowdrops.