All my oilstones have been gummed up for while so, while reprofiling a new knife with some new waterstones, I soaked the oilstones in a solution of water and Simple Green. To my surprise, all the oil and metal particles lifted right off without scrubbing. Without hesitation, I put my SharpMaker rods into this solution and got the same result. Bar Keeper's Friend and an abrasive pad require more effort for a lesser result. YMMV.