I used it successfully on my current project. Really just a clever way to wet blend quickly and efficiently. One key to keep in mind, is that he loads the brush and then just puts the white highlight on ONE SIDE of the tip of the brush. Ben very often puts too much white on and has to knock some off, so be careful how much you put on, and keep it on just one side of the brush, so that you can flip the brush to the other side when wet blending the darker shade into the white.
Although it could theoretically work with shading, he only uses with highlighting. Furthermore, he only uses with the final highlight (white) and a basic highlight tone to create a range of highlights. IOW, if you normally glaze on Highlights 3, HL 2, HL 1, then pure white, instead this method used Highlight 3 wet blended into white to create the other range of highlifhts. So basically apply basecoat, use loaded brush to highlight, glaze on shadows.
Edit: white=final highlight color. Of course you are not limited to white, but using anything other than the extreme of your highlight makes no sense since you are wet blending tones together.