Degreasing Undercarriage, Any Recommended Precautions?

[prix]

II was told awhile back that oil was leaking from possibly the oil pan (or worse, I just do not know). Car was up on a lift and there was a fair amount of oil from there on back to the transpan. I realize the oil from up front could have traveled back on the transpan by wind transferring it. T he seal on that transpan was changed about two or three years ago, so I would not expect it to be leaking. At any rate, going somewhere tomorrow to have it all cleaned off so we can poinpoint the leak. He said he would use hoses, etc. and I just started wondering if it's possible to do any damage with just spraying in that area. Any recommended precautions? I don't think water alone would get rid of oil , so he may be using some kind of degreaser. For what it's worth, there is no oil under the car in the mornings, Would help to have info by mid-morning tomorrow (before my appt.). Thank you...

[landar]

Opps. Guess it's too late now. A good cleaning would involve a degreaser and a heated high pressure water wash. There are not a lot of connections underneath but if you had the entire engine cleaned, it helps to 'bag' (plastic) anything electrical such as fuse boxes, coils, connectors, etc.