Wow. I don't even treat my car and truck as well as some of you treat your tractors!
The Cabota DOES get a rinse a couple of times a year, usually after mowing season. If it's REALLY filthy, I might get a bucket of hot, soapy water and swab the worst of it off.
I've got one bush-hogging job I've been doing for years. The owner only wants it done once a year, usually in August, after all the wild flowers have gone by. That means dust, seeds, milkweed fluff and dead dry grass everywhere, so it get's blown off good with an air hose after that job. Fire hazard, ya know, plus overheating from a plugged up radiator.
Vacuum out the cab (dirt holds moisture which creates rust, just good maintenance) and wash the windows when they get disgusting enough.
Other than that, it's strictly au naturale with exhaust soot and grease blobs on the loader, and poop on the tires...