[BoxsterSteve]

^
+1

At home in the driveway.

I used the garden hose to wet it all down, sprayed with 50% strength Simple Green, waited 5 minutes and hosed it off again.

Used the air gun on my compressor to chase most of the moisture away and fired it up to dry off the rest.

I just wanted to get rid of 15 years of dirt to get a baseline to watch for future leaks and such.

I'm under no illusion that it will stay clean for any appreciable length of time, given how most cooling air is drawn in from underneath, but it was worthwhile for baseline purposes.