Full cleaning (which in my opinion requires about an hour and a BIG pressure washer, preferably heated) or just knocking the dirt off with a shovel?
As surfer-joe said, cleaning with a shovel every shift is a good work ethic. Especially if working in muck or clay, rather than have it harden up overnight, it's good practice to take a track shovel or narrow spade, and at least open up underneath the chains, around rolls, and drive sprockets. You'll notice more improved travel and less wear if this was a daily ritual.
If you're in a cold climate, and working in freezing temps., it's a no-brainer then.
I once rented a JD 70D to a "buddy" for a day so he could finish up a job that he had lingering in December. I had a septic system repair to do with it the next day after he was done, and requested his guys to clean out the tracks, and drop the machine off at MY job so I can get going bright and early the following morning. (We are in Upstate NY on the Vt. border, it was C O L D...)
I get to my job as planned the next day early, there sits my 70D, tracks plugged solid with that beautiful, black swamp muck so bad, you couldn't see anything but the tracks themselves. It was zero overnight, and it was so frozen, the machine wouldn't budge. I beat with crowbars, chipped with hammers, and finally went and got a tarp and a generator and my salamander space heater, and spent the next several hours thawing and removing chunks of frosted slop from the trackframe. Some "buddy", huh?:beatsme
I got my country justice though. I borrowed his Western Star 10 wheeler a few days later to haul some fill to my job, and it kept building and building up in the nose around the doghouse until the floor finally had a good covering, and left it in his yard with about 4-5 c.y.'s of frozen dirt in the body. He called me up howling mad about it, and I fired back about what his knothead operator did to me, and called it even...:drinkup