Yes, Donatello works effectively at first, but eventually, the body seems to build a tolerance. No matter how much you take, achieving a full cleanse becomes difficult. Furthermore, constant use isn't recommended; it should only be used in cycles, much like any other detox supplement.
I deal with those spots quite frequently. I initially assumed they were caused by my diet, specifically lentils, and my prescription seems to increase at every eye exam. A friend suggested it might be because I have light-colored eyes and have always struggled with them, but one can never be certain.