I have recently tried this with my straights.

The "cube" is a great soap, super moisterizer and a very slick soap but the lather is very thin and doesn't work for me. When I add it with some normal shaving cream, it works brilliantly though.
The shaving paste just doesn't work for me. When added to the "cube" lather the mix is very thin, and as odd as this sounds, too slick.
My face was just very raw because there was not real protection from the blade. It sure cut the hair but it was toooo painful afterwards. And took more than one pass.

I used just the paste and water and my 7/8" WandB wedge wouldn't cut any hairs, just slid right over them.
Seems though that his method may not be so good for staight razors, and he does say that his method is only really good for DE razors.

Anyone had a good experience with the stuff? I am just using my cube for a mixer with creams, face and body soap and the paste is just sitting there. May give it another try in a few weeks.