CLR stands for Calcium, Lime, and Rust, which are the three problems it is designed to treat. CLR is an alternative to white vinegar and it is acidic, making it a more powerful cleaner than its natural counterpart. While this means CLR can remove more stubborn deposits, a CLR cleaner can also damage the finish of your faucet and potentially your pipes. In most cases, vinegar should be sufficient and it will protect your faucet, so it is the safer option.