"discard!" commit message for commits that should be removed while cleaning up the history

Hi,

I often add printf statements during debugging, which obviously should 
not end up in the final submission. My usual approach is to commit these 
immediately, into commits with a message of "DISCARD", so that when I do 
a final rebase pass, I can remove the debug code easily.

Would it make sense to add a mechanism that autosquash understands 
directly, and that could be checked for by a push hook or CI rule?

    Simon