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You can use greased valve grinding compound, it is grease and Silicone Carbide, but probably not course enough for the 150 side.

It is not expensive. The courser the grit, faster it cuts. You will...

Same as any other stone, 36 or 60 grit Silicone Carbide and steel cookie sheet. That is a 150 / 400 Norton combination India stone, much too course for razor work.

It does not look that much out...