I suggest following these easy steps below, these steps are also valid for turbo nozzles and vario/adjustable nozzles.
Caring for your pressure washer nozzles is simple and easy. Just follow the steps below:
Remove the nozzle from the pressure washer wand or trigger gun. Prepare a basin with lukewarm water and soak the nozzles to break up any dried dirt.  Once the nozzles have soaked for a minute or so drain the basin and collect the nozzles. Get a pin and use it to push out the remaining deposits left in nozzle tips. Wipe and dry with a soft cloth and store safely.