You have to pick:

Vomit can be cleaned off but a violin can't be de-smashed.

Except an original painting that old is probably very fragile. Is it going to stand up to stomach acid? I don't think so. I think both will be ruined by the process.

Smashing a stradavarius would be more fun.

I think vomiting on the paimting still wins, even if you assume it will be destroyed by the acid. Why? We have many copies of Leo's paintings that looks just as good, or better than the original. The only value in the original is the coolness factor. Hey this is the ACTUAL canvas he painted the painting on - isn't that cool! Other than that a $20 poster print is just as good. However, if you smash a stradavarius, its gone forever. Thus I would pick vomit.

Stupid violins. I appreciate art. Half deaf. Music can go <bleep> itself.

It doesn't say how much you have to smash the violin. Just smash it a little and fix it later.

Which is more fun to tell people about?
"Hey, I broke a violin!"
"Hey, I just upheaved the contents of stomach onto an original work by Da Vinci"

Vomit. Derp.

I'm less likely to get in trouble with the vomit option, too. People vomit unintentionally but it's a lot harder to explain away smashing a violin.

Depends, not all strads sound good and are more about the name and there are copies of Leo's paintings, but I would vomit on the painting because I played the violin for six years

I love that this is one of the more heavily discussed WYR pairings on this site. Gotta keep focused on the important stuff. :)

Smash-o-varius!