Something seems REALLY funny there. The stock 220 that I have is almost gritty, I don't even like it all that much because it feels like I've got a handful of sand between the stone and the edge. I can't imagine THAT stone getting clogged... I've never had one contaminated with oil before, and I do use three or four drops of Dawn in my spray bottle.
That is definitely not a normal thing, though! I'd be tempted to contact Ben and see what he says, he really knows his stuff.