I've given up on these, as even in hot water (hotter than I want to put my hand in for more than a few seconds) and sitting for up to six hours I end up dumping out chunks of these. They are not dissolving.
I use these tablets to clean my kegs, SS & glass fermenters. So simple. Fill with hot water, drop in a few tablets, wait overnight and they are clean. Simply rinse and sanitize and your ready to use again.
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.