[Zeke]

I have done this on several cars and I can't think of anything in particular that you need ot avoid other than the usual precautions. You will get water in your face, so it's a good idea to wear glasses. Don't leave anything on the paint and have a plan for cleaning up the driveway or area you are washing in before the grease goes somewhere you don't want it to go. Like from where birds or animals would drink.

Pretreatment and scrubbing on a warm motor and trans helps.