Knowing that these are meant to remove organic matter makes me feel better about these, but some elbow grease is still needed. Dropped one in and left it to soak, came back several hours later to find the majority of residue removed, but some remained and really needed scrubbing.
Whoever invented these is genius. Just drop in the indicated number of pellets, let sit an hour and lightly brush if needed. Works great! Gets everything. I use these a lot and really like them.
