Wow, I know that barium rhymes with quite a few words, like vivarium, herbarium, rosarium, samarium, aquarium, solarium ...!
Now, I am wondering if you refer to this kind of "pun":
Q: Why do chemists call helium, curium, and barium the healing elements?
A: Because if you can't helium or curium, you barium!
(healing and curing is clear, but for "barium": there would be baring, barring, bearing, burying ...)
And besides "BA" (referring to a bad rear or a bad equine species), there are some interesting ideas in the Urban Dictionary:
http://www.urbandictionary.com/define.php?term=barium
So, you might as well bury them (does somebody have an idea for a suitable or sulfury obituary?) - lol.