Cover the alternator and then use a garden sprayer with a mixture of almost hot water and clothes washing detergent to gently wash it down. I use simple green for the stubborn areas (got a few on my '65, the '01 doesn't have any yet). Then rinse it with the same sprayer with clean almost hot water to get the soap off. I also warm the engine up a little, too. Not all the way warmed up but let it idle for a few minutes. Then I treat the rubber and plastic with the same stuff I use for the tires, polish the chorme and aluminunum if I have time and it looks pretty good. Sometimes a soft scrub brush will help. Oh, yeah, before you start, clean the battery with a paste made from water and baking soda to kill the acid. Steam cleaning is not a good idea for the reasons others have stated (in my experience). Some are lucky with it, but I haven't been....