Here is a good test for Busch Aluminum Wash. Road grime, brake dust, and dirt have accumulated on this wheel.

Start spraying at the bottom of the wheel.

Spray from one side to the other.

Continue spraying..

Make sure all areas have good coverage.

Work the spray to the top of the wheel and let product soak.

Note the voids in the foam as the product emulsifies the dirt.

Spray more product where needed and continue to soak.

Soaking..

Soaking..

Wheel is now ready to rinse.

Start rinsing wheel with strong hose pressure.

Rinse from bottom to top.

Rinse..

Rinse..

Rinse thoroughly to make sure product foam is gone.

Check for any leftover product and rinse as needed.

Finished. Now dry it with towel and polish.

Here is another wheel covered with brake dust, road grime, and dirt.

This picture shows the WRONG way to spray product, which is from top to bottom.

Spraying..

Product is running down the wheel.

Product is starting the streak the wheel.

Note how product foam has run down the wheel onto areas that haven't been sprayed. This causes streaking and runs that are difficult to remove.

Soaking..

Rinsing..

Still rinsing..

Finished wheel now has streaks running down from top to bottom. Spraying from bottom to top would have avoided this.