According to a chart that someone posted awhile back, white is more coarse than green. I have some white - one is the hard, crayola stick kind and the other some French stuff, almost creamy, that a fellow Forumite sent to me. I don;t use either. Not because they don;t work, just because the green suffices.
If I remember correctly, black is coarse, followed by white, then green, and red is the finest.....more or less anyway.
Clean off your strop getting as much oil out as possible. Use rags, blue shop towels, whatever you have. Heat the leather and the oil will come to the surface (or at least be more easy to wipe off). Once you're satisfied, reheat the leather and apply your rouge like you're scribbling with a crayon. Sometimes it will sort of sit on the surface in flakes...that's ok, you'll wipe that off later. Keep rubbing, getting the rouge worked in to any and all areas. When you're done, take a blue shop towel and wipe down the strop.....very light pressure. Some areas of your strop may have a thicker application than others, don;t worry about that. It will work fine for your purpose. Once you begin getting good at stropping and seeing the results (which will be nil unless you start with a nice, sharp, crisp edge), you can refine your rouge application - maybe going back to oil or something.
