Did someone mention my rice grinder?
I will confirm that raw rice can easily clog a grinder, especially when ground in typical espresso ranges. When ground coarsely like french press you're probably less likely to clog, but why risk it?
I have a thrift store La Pavoni PGC conical burr grinder - not used for espresso for many reasons. I tried to use it as a spice grinder and it just couldn't handle the grind I needed for that. Tried to clean some of the spices out with rice and found it to be a decent rice grinder, but raw rice ground fine in the grinder will clog it up. I've had this little thing seize up a couple times, so I avoid fine grinds on rice, and coarser grinds work very well.
I use the rice for "cream of rice" like cream of wheat, oatmeal, grits or whatever. Also makes a good rice polenta. Nice, clean, steel cut rice. Would work good for cutting oats or wheat too I think.