Hello, I'm new so don't yell at me.:(
What about using one of those 3M foam sanding blocks? Seems it would conform to the shape of the serrations.
I have the 3m sanding block and I can't imagine it helping you sharpen your breadknife, it's funny I just got myself a gude and have been thinking about it myself, so I am about to order the dmt diafold serrated knife sharpeners, they look like exactly what you would need for a knife with a traditional serration instead of the scallop. The coarse is something around 350 or 330 grit, the fine is 600, the extra fine is 1200, could probably get away with just having the fine one.
The Diafold thingies are not wide enough in diameter for anything but the tiny serrations found on folders and even then they don't work well because they're tapered which means a constantly changing diameter being used. I have them and do use them for some really small serration patterns but no they won't work at all for standard bread knives.
How do you deal with reverse serration/scalloped knives like the Mac bread knife and such?