The Kenzan rake brush is a real "hero" when it comes to cleaning your flower frog / Kenzan. With its narrow but powerful metal arms, it can reach where it's otherwise almost impossible. A toothbrush / dish brush can help in some cases, but if you want to get your flower frog really clean, this is the brush to use. Using a dirty flower frog with organic material residues is an effective way to quickly spoil the water. Bacteria in the water will cause your flowers to die much faster. The Kenzan rake is also great for cleaning the metal base to restore its shine.