When I was transporting prisoners I hated spitters. We’d put a stocking over their head with a golf ball knotted in the toe. If they spit, it just drooled down their face. If they tried to get the stocking off (they were hadcuffed) they’d usually just end up knocking themselves silly with the golf ball.
Sounds as if that could become a patent idea.
Don’t know how you kept your sanity as a LEO. Maybe a second career as a public school teacher could be in your future.
That or just yank the front of their own shirt up over the front of their face. It pulled their head down and they spit on their own property......
This SOB would be dead if it had been my child he did that too.......even if I had to level the jail he was in too do it. Justice thru chemistry, physics etc