Finish by replacing the grime gutter and tuning the instrument if necessary. Your trumpet should now be good to go!
Step 11: Cleaning and Replacing the Valves (Save this for last!)
Select one of the valve pistons and run lukewarm water over and through it. Apply several drops of soap to the piston. Rub the soap around the exterior of the piston with your finger, attempting to work off any residue. Do not attempt to scrub the piston with a brush. A brush could scratch the piston and this could cause the piston to stick when in use. Now, using your index finger, attempt to rub out any residue in the air channels of the piston. Rinse the piston. Quickly, before the piston has a chance to dry, apply a good amount of valve oil and replace the piston in the correct valve casing. (The resistance between the water droplets from the rinse and the oil make the water-oil combination a super-slick lubricator, and this is why we cleaned the pistons last, so they could be quickly replaced in the valve casings without losing any of this water-oil combination). Repeat this step with the remaining two valve pistons.