I take the lower burr out every other month for a thorough cleaning. I also use compressed air every week to clean the burrs and brush out the burrs every day. The effect I noticed was due to the rice and nothing else. My maintenance on the HG One doesn't allow it to become dirty.

I took the lower burr out one day before running the rice through the HG One so the grinder was very clean and I still noticed a difference.

We need to get digital, decent quality, microscopes in our espresso toolboxes now so we can start watching grinds, burrs and other minutia! It'll be like the new group thermometer, only now it's imaging for grinders!

I apologize if my comment may have seemed stand offish, I just wondered 80 lbs. seemed like an already perfect setting for a conical grinder. We are here to learn, absolutely! It seems some folks are for rice and some feel its just another way to prematurely destroy a grinder burr. I admit it is scary considering some burr sets are well above $100 some even $200. So there is a risk involved in exchange of data/experimentation.

I will happily perform SEM/optical tribologcal analysis on the burrs of two K10s. PM me if you wish to send two unused K10s and I will examine their cutting surfaces before and after I subject them to a consensus approved volume of coffee and rice. Ha!