Hard not to assume that there is some trolling going on. But, if you're serious, I'll answer. I have owned two construction companies, and rented countless porta-potties, for long term placement on construction sites.
Here is how they are cleaned, and how "sanitary" they are. The are typically cleaned weekly, so if you are lucky enough to swing that door open one hot summer day, the day before cleaning, you might have the urge to puke. When the cleaning truck shows up, the whole process takes less than two minutes. The truck stays running. The cleaner grabs a big hose from a truck mounted vacuum and sucks the contents out, right through the seat opening. While this is happening, a five gallon bucket, with a bit of blue odor control solution added, is being filled with clean water. The blue water is then dumped down the hole. If the interior is really gross, the cleaner occasionally takes another bucket of clean water and tosses it around, while standing a few feet away, to avoid splash back. If that's your definition of sanitary, go for it. Me, I avoided then whenever possible. The other issue to remember is that entering a construction site for any reason other than legitimate business ones, generally means you are trespassing.
