You're just bending over the very tip of the blade so that its more of a scoop. You're just running the blade along the hard rough metal with the blade at an angle a couple of times. Always in the same direction. You'll feel the rough side of the blade.
The Gibson binding scrapers use a tool more like this StewMac one.
Ok, here's a pic of my scraper, the edge burnishing is achieved by just holding the blade edge at 45 deg against a hardened edge (I use my vice jaws) and dragging the blade with some force along it so as to fold the the sharp edge over.
Now you can drag that edge along your binding with no risk of digging in, also you will find it takes much less effort to remove stain and varnish than a straight Blade.
Hope that explains it.
Btw
I use the same procedure to make a fretboard scraper.
Thanks everyone. I'm not the OP but I learnt a lot from this thread which should help me do a better job on the binding next time around. My current binding turned out OK, but it clearly could be better. It passes the "looks OK from 2m" rule, but not "looks OK from 2cm".
Thanks to everyone for the detailed responses.
My weekend will be a scraping activity!