What can I do to salvage a gas pressure washer that fell into my pool... running?

Drain all the fluiids and take out the spark plug. Squirt a light weight oil in the cylinder and pull the cord a couple of times. Drain the gas tank and lines and rrun Ethanol through them. The biggest issue that you are going to have is drying out the magneto (coil) it is high voltage and water will short it out. Set it in the sun to dry for a day and then put new oil in it and then fresh fuel, new plug and give it a shot,