I use to live in SoCal, and If you looked at my ski's.... you would never know that they were ever used in salt water. So..........
PRE-PREP:
1) clean the boat, inside and out
2) Wax the hull
3) use silicone spray on the pump parts.
4) use BPR spray oil or silicone spray to protect everything in the engine compartment.
After a run:
1) wash the boat inside and out
2) Flush with fresh water. (or better, use salt away)
3) flush the engine compartment with fresh water.
4) re spray the metal parts with your protection oil.
It's a pain to run in salt water... but if you keep it clean... you will never know, and you will never have excessive corrosion.