We have a theory the RezBlock is enhancing the effectiveness of the herb, by transferring more of the vapor to your lungs, since its not really sticking to the glass, nor really collecting in large amounts.
Some break down occurs, as the water/RezBlock is agitated. You can see a larger piece start to collect, but the agitation will cause it to break down. It will stay suspended in the water, making it opaque. However, it is in far less amounts than prior to RezBlock. That and the personal experience of feeling better and more efficient use of my meds, leads me to believe (and others) that the RezBlock aids, not in the extraction... but in the transfer.