Executable code and Visual editing?

I’m looking to include some executable PHP in a page. Using the “HTML” editor (along with the Exec-PHP plugin) I’ve been able to add the code and have it function properly.

However, when I return to the “Visual” editing interface, the code gets destroyed. While I’m comfortable editing post content in HTML, we have authors who will need to use the “Visual” editor.

I’ve been searching for days to no avail. Is there any way for executable code and “Visual” editing to work together?