Guys,
I bought a wand at Harbor Freight that you hook to compressed air and put the secondary tube into a mix bottle, I used simple green mix. I wrapped a cheap tarp around four 2x4s for a capture area under the car and cleaned the front of my engine this way. Worked great and did it right in my garage. Worst part was the simple green mist, need plenty of ventilation.
Also lifted the car on my lift and did the underside, just hung some cheap tarps so the overspray didn't hit the walls, bench, whatever.
The wand was less than $10.00.

John D., WAZOO traveling companion to BG