I think we might have gone to a lot of trouble that was not necessary.
All we needed was a chipper standing at the Anti-Slabbing table with the list.

Every chipper that walks by will ask "What are you doing."
The Anti-Slabbing chipper could just point to the Slabbers table and tell them to go and take a look.

The chippers should run right back to sign the list, no questions asked. <g>