I have a yellow coticule and yellow coticule slurry (cotigura) stone. I'm buying a blue coticule.

Any reason not to use the same yellow coticule slurry stone on both my yellow and blue coticule hones?

As long as I wash the slurry stone in between, any risk I'll import the coarser blue stuff to my yellow hone that way [ie any risk of cross contamination]?