Send a memo out stating:
"Any layer which does not conform to the office practices and CAD standards set forth, will be deleted along with the items belonging to that said layer."
When a drawing comes back to an individual and they have to redo their work, the ***& will hit the fan. Someone upstairs will have to step in and make a formal announcement that this is not acceptable and that the standards must be heeded.
I have a guy who did that to me. That's how I came up with the idea. It only had to happen once and I let the staff all know that our standards are there for a reason, and I condoned the deletion, if only for a lesson learned.
Let's just hope your higher ups are just as reasonable. 🙂