If you're looking for a concrete mortar dissolver, there are several options available in the market. One effective solution is to use a commercially available acidic solution specifically designed for dissolving mortar residue. These solutions typically contain strong acids like hydrochloric or phosphoric acid, which can break down the bonds in dried mortar, making it easier to remove. It's important to follow the manufacturer's instructions carefully when using these products, as they can be corrosive and require proper safety precautions.