I'm not an expert at all, but it seems that it would be a bitch to deal with, being gloopy and gross, while providing no or little advantages. When you grow in soil you want the roots to get nutrients out of the soil. When you replace most of the soil with water you're taking all the nutrients that would be in the soil out. You'd be only replacing those nutrients with hydro nutes in the water. The point of hydro nutes for hydro set ups is so you get rid of the soil, so why add a little bit?
doesn't seem like a great idea to me but I could be missing something