Hi ! Try using magic eraser , it will be able to clean uneven surfaces .
Hi ! Magic eraser is an amazing cleaning sponge !!!! It is white and you only use water on it but it takes off scuffs of walls of floors. It cleans , especially , anything that has texute...metal , walls , leather ... Maybe you can find it on Amazon... I don't know if you have that site where you are ?
We found ours that difficult like yours. My husband bought a Hurricane Turbo scrubber and it did the work for us! We use our own favorite cleanser. It is also great for cleaning ovens, stove ranges and even auto tires! They are great and you can get them at Walmart or order them online through Amazon.
Use 1/2 cidar vinegar solution with water