swarf and slurry

When I'm done honing on a coticule, I let the slurry dry back onto the surface of the stone. I've read a recommendation somewhere on one of the Belgian sites that this is what you should do.

Do I have to worry about metal particles building up? I know they don't 'load' like on the Nortons, i.e. get stuck to the grit and clog the pores, Belgians being non-porous. But if I'm never rinsing off the slurry, will it get contaminated with metal?

I haven't had a problem with metal buildup in the slurry when honing on a coticule. The reason is that so little metal is removed when all you are doing is a few passes in order to keep the edge sharp. If it is a worry, just rinse it off every few honing sessions and re-slurry with a cotigura (a coticule rubbing stone).