Opinions on Mud?

I have made some choices on equipment and techniques on tips and things I have read in here, so in reading on how make a refugium more effective, I came accross Miracle Mud, not exactly sure what this Mud is, so I would like to hear from those that have or use it and how it worked out for them.

 

I like what I read about this stuff "Walt Smith's Refugium Fiji Mud" I wonder if you can put a thin layer of live sand on it? That stuff looks really muddy

 

From everything I've read of people that have it, it doesn't do anything different than sand but it's good for mangroves and other rooting algaes/plants. Our original sump had miracle mud in it when we bought it & we ditched it & replaced with sand. To be honest, the guy we bought it from was running it on his large tank & it wasn't looking all that miraculous .

 

That was my first thought, that it wouldn't work any more differently than live sand, hhmmm!!