The correct answer is Zero Tolerance by all involved. Players, coaches, officials, ADs, site coordinators, spectators, school administrators, etc. Sanctions should include straight rec card for athletes/coaches; ejection for spectators; suspension of participation/attendance privileges, etc.
I suggest a posted policy at all gates, signage inside facilities, and pre-game public address statements.
Then again, we are talking SCHSL and local school athletic administrations, which are, quite often, clueless.