TE has it right. The only way to thoroughly clean up a seawater-dunked bike would be to fully disassemble it to parts and wash each part thoroughly, then repaint and relubricate before reassembly. Even then there could be salt trapped in areas such as frame tubes.
If you just need it for short-term transportation because you have nothing else, a freshwater rinse of anything that had salt in it (I'd include the engine/transmission in this if the oil showed evidence of water contamination) followed up with some WD40 &/or acetone, then fresh lubrication, should get you back on the road for a bit. I wouldn't expect it to last long, though.