Bill -
I bought some of those last year and discovered, just as you have, they are too thick to use on a Dewalt blade holder. They seemed like such a good idea too. I bought some popsicle sticks at Michaels and glued various grades of sand paper to the sticks. I cut one end of the sticks to a point to reach in places better. I may have gotten that idea from one of Steve's videos. They DO work but of course you still have to sand by hand. Live and learn.
Barry