I started using this product when it first came out. At that time I was very pleased and impressed with it. So impressed that I went and bought a couple of cases of them to keep them on hand. You see, I had four kids at home, plus all their friends and a house that had white walls. Or they were supposed to be white. I had one child who loved to write on the walls AND the wood framing. These erasers were a blessing and even though the package said to throw them out after used, I would rinse them and reuse them. It took a long time for them to wear down to nothing and during that time they did a lot of cleaning. I even used them on my pots and pans when scouring pads were not available in the house.
I have noticed though, that as they became more popular and more people started using them, the quality of them went down drastically. No longer could I clean the walls in a whole room, as the erasers would fall apart in my hands. The price went up, the quality went down.