One place I worked had one driver was a bit of a pig and his cab was his pig pen and hog wallow all in one.
The boss kept telling it to clean it out or he would get one of the mechanics to do it.
Well after about a week of telling him, I got the task.
The boss told me to open both doors and take a fire hose to it, take the camp radio out first (Just a note here, truck was an old Hayes HDX off hiway logging truck, not much electrics in it)
I had a riot, hosed the roof off, stuck the hose down the defroster, washed all the garbage off the floor.
But the best part was the seat, boy did it get special attention.
I soaked it, must have taken a week to dry.
Man was operator PO'd
BUT
The next time the boss said something about his cab was getting a little dirty inside and he was going to get me to clean it again.
The truck got cleaned right away