I have seen that stuff and it seems like it might work, but changing everything out looks like a PITA. Having to remove every bit of the regular coolant doesn't seem easy. I might use it in the case of a complete rebuild though.
I put NPG+ in my Pantera, I had a clean system,which made it easy.It works well and is non toxic.Downside,do not get it on your skin,it burns,doesn't leave a mark though.Price is high.
The stuff looks like a light oil,same color and probably like a 10wt viscosity.
Good luck, Guy