💡 How To Deep Clean Your RV Gray Water Holding Tank 💡 Deep cleaning your RV’s gray tank is quick, inexpensive, and literally works while you sleep! 😴🧼 🛠️ What you’ll need: fresh water, Dawn Ultra dish soap, time Steps: 1️⃣ Close your gray tank valve. 2️⃣ Fill your gray tank completely with fresh water. (Cleaning only happens where water touches… fill it up!) 3️⃣ Pour at least 20 ounces of Dawn Ultra dish soap down your RV’s kitchen sink. (No such thing as too much Dawn! If you see soap foam