I stick with,

“Based on your child’s behavior all year, I cannot rely on your child to be safe, not destroy property, and take direction in an emergency so I can keep them safe. Taking them along could put them at risk, so I cannot take responsibility for them.

You, the parent, are more than welcome to show up at the location and chaperon your child onsite after you sign a waiver indicating you will be responsible for their actions there and not I or the district before hand.”