Several comments based on my experience:
First: The burnisher needs to be harder than the scraper. The side of a screw driver or socket extension did not work for me. I made mine by cutting the stem off a diesel engine valve, and setting it in a wood handle. Very smooth and very hard. A good burnisher that doesn't drag on the edge is a must. It does not have to be very long, as it needs to be pushed straight down the length of the scraper, not across it an an angle.
Second: A little light lubrication on the burnisher makes it much easier. I usually just drag the burnisher behind my ear, or alongside a nostril on my face, although any light oil or WD-40 will work.
Third: It doesn't require a lot of pressure. One flat stroke, a couple at a slight angle, and a couple more at a little more angle will establish a bur you can feel with a fingernail. However, more smooth strokes are better than a few hard-pressured ones.
Fourth: For hogging off wood around a knot, I go straight to burnisher from the mill file. For smoothing out and finishing a surface, I hone the edge. I just lay the scraper against a squared block of wood to keep it vertical.
I struggled when first starting out. Getting a good burnisher was the main thing that turned things around for me.