OMFG.. ok stop whatever you're doing.. you are in panic.. and you're making everything worse.. whatever your doing... STOP
You need an extreme overhaul..... I am afraid to tell you that if you choose to do this, it will be at least 8 hours of work.
First, unplug the keyboard
Identify 3 level of switches. MAKE a chart!!
Level 1, completely normal
Level 2, slightly damp and wet
Level 3, completely damp and wet.
Now disassemble the keyboard.
De-solder all level 3 switches...
Open them up, if there's no rusting, just allow to dry, lube up the stem, and reassemble.
If there is some rusting, then throw away, and purchase replacement.
For the Level 2 switches, press the switch down, and use a blow dryer to blow cool air, on the COOL setting into the switch.
If it returns to normal great, if not, desolder, disassemble, check, if no rust, let dry, if rust, throw away and add to order list.
You can leave all the level 1 switches alone.
Now for the rest of the stuff. Simply allow them to dry.
For the board itself, if there is dampness in the middle between the metal plate and the pcb, you may consider blowing air across the middle, again, use the cool setting.