Hi...
it's not that we have a 90% spam 10% content ration..
That's not a very high standard to compare the situation to! 
To be honest I don't understand the reluctance to enable a couple of people to implement this. Is there something about the situation I'm not understanding?
A greater than zero number of community members find the spam unnecessary and there are at least a couple of people willing to provide the mouse clicks required to delete it more promptly. Less spam. More time for the existing mods to do more useful things. And I could delete the spam with one click (I assume) instead of typing in a bunch of stuff and waiting for a moderator to delete it.
I would appreciate it if you could please explain the reason for this not being an acceptable solution for you.
Thanks.
--Phil.
P.S. FWIW with the current spam volume I think captchas would inconvenience the forum community more than the spam.