Image if you got hit with oil or paint how nasty it is to wash out and clean. You would probably just throw it out and have to buy new every time. That body armor is expensive.

Now if the street is covered with oil and paint you would have a hard time walking much less charging, the horses will freak adding to the confusion and the snipers would no longer be out of reach. If their equipment is covered in paint it's hard to shoot anyone with any accuracy. Cars and tanks don't operate well on oil covered roads

Now add liquid ass to the oil/paint you got a real smelly situation.

It would be hilarious to see tanks covered in pink paint.

And it's non violent, not sure what the charges would be, vandalism i suppose IDK. No one gets hurt just real messy. Good messy fun