From my experience the cubes, lumps will dissolve to a point that look like small black grains. They will eventually disappear.
I usually replace when they break down to a small grain size.
Now my problem is finding more to purchase at a reasonable price, my go to store is out and I was informed they will not have any more until next year.
One does not simply throw around the phrase "molested cat excrement" without photographic evidence to prop up such an absurd and scatatological statement.