Simple components are usually OK to salvage IMO...cel phones etc. have these micrometre-class circuits open that easily corrode or 'jump' with dirt in there...but larger components and usual pedal solders & circuits are quite coarse...so it could well be cleaned. This is how I'd do it if it was _completely_ soaked:
Remove all IC's that come off from sockets, etc. parts
Put in distilled water & ultrasonic vibrate it if possible, if not, just soak the perhaps 'invisible' dirt loose and rinse well
Dry with blowdrier, then put in uncooked rice or silica gel for a while
De-oxit the hell out of it
Use WD-40 or such for switches etc.
I would venture at least the actual circuits could well be salvageable.
Dee
"When life's a biatch, be a horny dog"
Amps: Marshall JVM 410H w/ Plexi Cap mod, Choke Mod & Negative Feedback Removal mod, 4x12", Behringer GMX110, Amplitube 3/StealthPedal
Half a dozen custom built/bastardized guitars all with EMG's, mostly 85's, Ibanez Artwood acoustic & Yamaha SGR bass, Epiphone Prophecy SG, Vox Wah, Pitchblack tuner plus assorted pedals, rack gear etc. for home studio use.