If you're determined to dress that wheel, I would use a vertical sander and and just touch your cut off wheel to it ever so slightly. If you don't have a vertical sander I would mount a grinding wheel or a handheld sander with the face vertical and do the same thing. Make sure the sparks are not going towards you and of course use eye protection. I work with these things all the time and you sometimes have to do things that are unconventional. I would suggest that if this makes you nervous, don't do it and just suck up the cost. Be careful!