Polishing with stone slur / powder

Hello everyone, I recently received my first Stone, a Cerax 700 and I managed to let the slur from the stone deposit on a small container. I let the water vanish away and now there's plenty of powder on it which can be easily removed and used for takin off the patina on my Tojiro Shirogami Steel. I never did it before and I wanted some suggestions on how can I use it on my blade. I saw someone talkin about placing it on a cork (I thought about a cork tap from a wine bottle if that can be useful). But how should I really proceed and is there some other ways of doing that?
Thanks for your help !

I use the collected slurry and apply it with used sandpaper abt 600 grit and for safety reasons.... hv a large eraser /rubber as a backing. It is also soft and conform to the contour of the grind..

Take care not to overgrind your edge.
But you may use it with a rust remover.