Review on Dryer Balls XL - Premium Eco-Friendly Laundry Softener & Wrinkle Release | Long-lasting Reusable Alternative to Liquid Softener, Dryer Sheets & Wool | Vegan & Sheep Safe | Includes 2-Year USA Warranty by Steven Ripley

These are weird. I envisioned them being made of softer plastic, but they're tough, so they make a huge noise as they thump in the dryer until they get stuck in a sheet or piece of clothing. However, one of our cats is drawn to the noise, so he runs into the laundry room to chat and listen to them. I'm not sure if he's imagining a squirrel or an impending home invasion, but he doesn't seem upset, just curious. They say you can use them with essential oil if you want to add fragrance to your laundry, but I'm not entirely sure how that's supposed to work. I tried putting oil in the hole at one end but it's so small the oil drips and then runs down the hard plastic and gets everywhere. For washing I would give them a 3, but for entertaining cats - heavy. 5, so we average that to 4.