The "friendliest" method I have found is as follows:

Get a small putty-knife/scraper from the hardware store.
Get a dead shipping box for a washer or desk or something.
Put tranny on opened up section of box and scrape goop off with putty-knife. Have a soup can or coffee can handy for putting bit bits of kaka in and scraping knife into. When done with scraping step, mess on cardboard can be dumped in can , lid put on and whole thing put in garbage.
Then you must choose.
REALLY friendly... at local car-wash with some simple-green and a plastic scrubber. Car washes have grease separators and must dispose of the sludge properly.
Somewhat friendly... Use oven cleaner and a plastic brush at car wash... watch out for fumes.
Not so friendly... Simple green or oven cleaner in the driveway.

Then I give it a sluice with WD-40 and a slathering of the input shaft with grease to keep it all from rusting until it can be installed.

Mike!

Simple green works great. Soaking down with Dawn dishwashing detergent works pretty good too.
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-------Robert, '93 940t, '90 240 wagon, '84 240 diesel (she's sick) , '80 245 diesel, '82 Mercedes 300SD

I've done it starting with the scraping method, then moved on to simple green with a coarse brush... perhaps even a brass wire brush.

I've cleaned the inside of my Jaguars (17 quart) sump in the bathtub...that was eight years ago, and the stains are still there. Not recommended, though it worked fine.

-Matt
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-Matt '70 145s, '65 1800s, '66 122s wagon, others inc. '53 XK120 FHC

I use WD40 -- it's a terrible lubricant, but an excellent degreaser. Scrape the really thick stuff off with a screwdriver, spray liberally with WD40, scrub with cheap 1" paintbrush, spray more, scrub with toothbrush, dry with paper towels.

Works for me...

I usually use an old chissel or screwdriver to scrape of most of the oil-sand mixture. Then I take a bit of petrol and an old paint brush to nicely clean it, while using an old cloth to wipe it off (non-washable by then...)

Do put some paper/cardboard under it though, you'll get some nice big stains on the floor/driveway otherwise... Petrol isn't too toxic IMO, but maybe you do find so. To clean a M41+OD I would need half a litre of it.

It's not a nice job cleaning it, but imagine putting the thing in dirty: even nicer...

cheers, ben
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P131, '65, B20B+M47. P131, '69, B20E+AW71L+LSD. (www.tinustechniek.tk)