Anyone Ever use A Final Flush Solution

Such as maybe the lineup made by grotek?
They have two websites :

www.grotek.com and www.grotekusa.com

It comes in multiple flavors, as well as regular and I was wondering if it actually works and is worth the 20$....Personally I have never used them, just water to flush two weeks prior to harvest.

Mmmmh, sounds fishy to me. The whole idea of flushing is to flush out everything except clean H20 (and maybe some molasses). I guess someone out there is buying it though.