Already acknowledging here how stupid this question sounds, I'm genuinely curious if there's a less-messy way to clean-up the underside of the Disco. I'm trying to trace down some sources of various fluid leaks but it's SO hard to tell where they come from since the bottom of the engine/diff/tranny area is so schmoo'd up with grease, dirt, etc. Do you just get under there, get after it, and let all the crud rain down on you? All while laying in the wetness of the now-soaked driveway?

 

I personally lay a little sprinkler under neath the vehicle, and run it at a volume strong enough to wash away debris, but not strong enough to damage anything. That is mainly for mud/debris, but you can do the same thing with say a foam degreaser, let it soak in, and then rinse it off with a sprinkler laid under a vehicle.

The cleanest my 99 D2 ever got underneath was during Hurricane Harvey though. I had to drive thru right at 3ft deep water (not counting taller waves made by other vehicles/boats/military trucks) and after doing that a total of 6 times at 3/4 of a mile each the underside of my 99 looked like it had just rolled off the assembly line lol. Not a single drop of water made it's way into anything on my 99 D2 which truly impressed me! Both my 05 Jeep Wranglers would get water in their front axles if you just crossed 1 creek crossing for example until I added the $$$ seals to the front axle tubes.

 

Best thing since sliced bread

 

I find the generic brake cleaner to do a fantastic job cleaning around oily spots. Helped me find the power steering leak I had.

Also the greased lighting product from Home Depot does a fantastic job.

32 oz. Super Strength Multi-Purpose Cleaner and Degreaser

https://www.homedepot.com/p/300802077