I pretty much do exactly what MelbourneFinn said, I clean the wheels, go for a bit of a drive, then clean again.
But then equally I drive my car like this so perhaps don't listen to me too much
325/30r20 Sport Cup 2 tyres don't work on gravel - this road was about 15km of gravel plus this ford
At about 100mph you feel like you're floating. But it was fun to drive through a river!