Gentle Fist requires one to press a special point on the body and insert chakra into it, but parts of the move requiring a certain manner of touch. The only thing that would allow them to affect him in that state would be if the Byakugan can see tenketsu on fluids, which I doubt, and then apply pressure and chakra onto the point, which I believe would not be effective... Ever tried giving a body of water a massage? I havent, cuz there is little to no sense to it...
But that generally refers to the usual nerve-pressure looking version, I cant say for the other technique that doesnt require actual touch although I find it hard to believe some of those technique actually give the same effect like an EMP does to electricity...