I love mine. I have a 3M very fine (dark green) and it's what I use to finish all of my blades. A spray of WD40 while the belt is running will make it blend things a bit better. Its more forgiving if you slip too. Some of these scotchbrites will remove alot of material.
I have a medium "Bear Tex" belt (maroon), and it's abrasive enough to throw sparks. I used it on a tanto once, and it completely washed out my grind lines. That one should be plenty rough for what you're doing.
BTW, these belts last forever. I just keep soaking mine in a bucket of hot water with dawn, and brushing them with a stiff nylon brush. The WD40, should you go that way, will kinda gum up the belt after awhile.
They kind of stretch and contract alot I found. Some days they are so tight I can barely get the things on. Other days they are loose and try to flop around on the grinder.