If you got anything on the circut board and its been sitting there corroding, you could be screwed.
with that being said. I would take some de-ionized water to clean up the metel peices, and a little isoproply alchohol after its all dried. (to dry the metal peices and prevent more corosion, try putting the pieces in a some tupperware with rice covering the pieces)
I have repaired a few digital items this way.. and the S5IS is a decent enough camera to not totall call it quits.
THere is a BETTER camera reapir guy in columbus, but ill have to do some digging to find his name/number.
Also, the guys at MidWest Photo on High would be the guys i would talk to. They know some pretty good repair shops, and i think the one they reccomended to me was United Camera in Illinois, but there was someone local as well..