This pop-up sponge is another great zero waste swap for your kitchen. Made of 100% vegetable cellulose (wood pulp), these kitchen sponges feel and function like traditional sponges but are completely plant-based, plastic-free and compostable. Directions 1. Soak the sponge in water to watch it expand for a few minutes 2. Use as a regular normal sponge Disposal Cut in small pieces, then place in the green bin to compost or directly compost in the backyard.