Tanning paper with Tea, Coffee?

I like everything about Bergger Cot 320 paper except sometimes it's a
bit too white and I'd like just a hint of warmth in its base. This made
me think of stuff we'd do back in undergraduate school when we'd rinse
prints in coffee, tea and such.

What is the "real" danger--archivally speaking--of doing a dilute tea
rinse on the paper? Tannic acid can't be a good thing in archival terms
so are there recommended final rinses that would leave the mild tea
stain but eliminate any acidity?

Thanks for all the good info!

Dan

-- 
www.DanBurkholder.com
www.TinyTutorials.com