Has anyone here tried this product in the 12 volt boat fridge sounds like it could help keep the beer cool.

techniice.com/reusable-dry-ice-packs-information/?SID=vl1c7gdbpdc650lrbgk87rufl6

Techi=ice make great ice boxes with a lifetime no-questions guarantee, and they chuck in a bunch of those things free when you buy one. They're not worth the money, any money really, more of a free bonus product. They don't work amazingly differently to your standard cheapo ice pack. The difference is that you can blast freeze them to -190c if you have the power to do so. I'm guessing you don't.

Agree with Dave. Not much different from normal freez brick. I have a few, hardly used them.
Bought a few sheets on Boat show.
Techni Ice reusable dry ice packs / ice gel packs start as a flat sheet and absorb water through a special perforation
technology in the surface of the product.

Just a water in funny shape. Can your eutectic freeze them, probably not, try normal freez bricks.
My suggestion, more polystyrene outside, if awkward space, foam spray insulation .