The method I use is after every run out on the track I first remove the wheels, body, fuel tank and wing. I normally block off the inlet fuel pipe that comes from the tank to the carburettor. Once all is done then I use my air compressor that I bought from Sedan it a 20L tank and does the job very well I use my air pressure at 3 and half bar with a dust air cleaner gun. It has a long tube fitting for all the hard to get places. Then I will use clean green mixed 90% and 10% nitro fuel with a brush to get the rest of the sand off the car. Make sure that you do not get any cleaning detergent in the carb or electronics. Wd 40 is then sprayed on very lightly and then once again with compressed air will remove let over WD 40. It’s a good practice to use some after run oil in the motor to spot the motor from clogging up. One thing I do is to make sure that I cover the air cleaner, or replace with clean one and cover with sealed bag to prevent dirt getting into the carb.Finally see that all screws are tight and replace broken parts if any.

There are many ways but this is how I keep and maintain mine and it looks good as new for every day out on the track.