I don't know about #41683, but I feel like the clay does pick up stuff. I think the important part is not to eat solid food, so the psyllium/clay can touch the walls without food being present. Just cuz it doesn't look like mucoid plaque doesn't mean that stuff isn't being released.
In blessed herbs case, they say that if you eat solid food the cleanse won't work as well as in, the rubbery stuff won't come off. But... I think whats really going on there is that the food mixes with the mixture, making it harder to detect that the rubbery stuff is there.
LisaG