Primary Palette with Water Soluble Oils

I"ve been trying different brands of water soluble oils. First was Grumbacher, then Winsor Newton and now finally found the best; Holbein Duo Aqua Oils. They are just like working with oils. Loveing them. Anyone use a varnish on these? Think I'm going to fix that highlight on the front rose. Didn't see it until just now!
"Pitcher and Roses", oil, 4x3 inches.