Bests & Worsts Reviews from Amazon

I've used both the 2.5 and 5# freezer blocks for several years. When they are new they work well, but drastically decline. I own an ice cream company and we use these to 'replace' dry ice for some applications. After many cycles of thawing and freezing they have ALL now lost their efficacy. (We have about 15 or so of these in the two sizes.) Definitely not a dry ice replacement as they claim to be. After about 20+ cycles, they just don't freeze as cold anymore or stay frozen as long. I have reached out directly to the company twice, and they have not responded to my friendly questions about decline. I am disappointed.