The grind wheels take a bit of dexterity to get good results. Otherwise the finish looks like it was ground with a small wheel not the straight spine to edge factory grind marks.

Reduce the marks with a progressively higher grit number and make sure with each new grit you grind out any scratch marks from the previous grit. Otherwise you won't be able to get a polished finish.

If you are going to leave it brush finished then make sure the scratch lines are perpendicular to the blade. Also, the heavier scratch marks will tend to be camoflaged by the finer ones so the brush finish is a bit more forgiving that way.

One thing I find that is misleading with grind wheels is that the appearance of the scratch marks gives a false impression of the depth of the grind. This threw me off when I used them since it looked like the grind was deep when it really is not, unless you strap in a 40 or 80 grit stone and attack the blade with it. The play of light gives an optical illusion of unevenly ground surface.

How much did you pay for the dremel, if you don't mind me asking?

I am curious, I picked up a no name flexshaft 1/3 HP 22,000 RPM motor with a 5/32" Jacob's chuck handpiece and a pedal for $54 on e-bay. The quality is not Foredom or OttoFlex (from OttoFrei where I got my first flexshaft) and the flexshaft is non standard but definitely worth the money.

I find having the pedal makes it much easier to control. I even tried the pedal on the dremel and having the speed controlled by foot gave it a significant improvement.