Clean with soap and water first, rinse with plain water second, then sanitize third, all in separate containers or buckets. Sanitizing solution can be 1 tbsp. bleach to 1 gal. water, let soak for 10 min. then air dry, or straight 3% hydrogen peroxide will work too for spot sanitizing. Reassemble parts using food grade spray lubricant as necessary; don't use vegetable oils or sprays as they can turn rancid and sticky. In the meat room we'd let the grinder parts air dry overnight then reassemble the grinder in the morning just prior to turning it on; if you didn't use food grade silicon spray to lubricate the knife and plate they would overheat and cook the meat by the time the worm gear got the first meat to it, then you'd have to tear down the grinder, soap, clean and sanitize, put it back together with lube spray this time and then start your grinds; not only a royal time-waster you could do damage to the plate and knife set enough to have to use a whole new set - I've seen knives chip or plates chewed up, the temper destroyed in the metal, knives so hot they turn blue!
One of the most important areas to clean and lubricate are the threads between the throat housing and the tightening ring. Scrub with a fine brush (like an old baby bottle brush, that's what I use) to make sure all meat particles are removed from the threads. If you don't, gunk will build up between the threads and wear down the threads over time until your ring will be so loose you can't tighten it down on the throat, ruining BOTH the throat and the ring and you have to replace both. My 1 hp. Cabela's grinder is a $400 machine, something I don't want to replace unnecessarily, for sure!