As far as spraying water from a hose into your exhaust tips, i suppose if you "limit" the amount from the spray nozzle, you might be OK. I personally just do not see that as being a good detailing choice. BUT as others have suggested above you should be fine if you start and run the vehicle immediately to have the engine exhaust heat evaporate the excess water out.


Interesting true story about spraying water up a tail pipe:I saw a youngster washing his parent`s car in their driveway while I was walking through my neighborhood. This young person did exactly that: took the hose-n-nozzle and directed it up the tail pipe not in a short burst, but for some time. I hollered at the youngster to "STOP" which he did and then knocked on the door of the house to inform the vehicle owner what was going on. The person who came to the door looked rather upset that I would holler at his child after explaining what was done and why I thought it was not a good idea. The kid was only trying to help clean the vehicle to the best his limited knowledge. This was probably the same youngster who was about to take Comet cleanser and a Brillo pad to remove the bugs from the front of the car. Good intent, bad results. Ignorance is bliss, but what you do not know may kill you (or damage the engine in you car).

As far as cleaning the INSIDE of exhaust tips, I use 3M 000 Synthetic Steel Wool (Yes, they do make such a product) and chrome cleaner OR Meg`s M105 Compound and a lot of "elbow grease" to rub/abrade/scrub them out. I then use Optimum Polymer Technologies` Metal Polish for the final cleaning and polishing (my go-to preference for chromed or stainless tips)

Someone within this forum suggested using oven or grill cleaner spray (It is burned carbon from food, but not petroleum products) to clean the inside of exhaust tips, but I have never tried it.
I also have some pre-VOC era aerosol cans from Ford Parts and Service (Ford Part No. D9AZ-19579-A) for cleaning out cylinder heads to remove the carbon in the combustion chamber, but I have seldom used it.

I know Pinnacle makes a specialized cleaner for exhaust tips: (reference: https://www.autopia-carcare.com/pin-...l#.YFnTFVVKj3g) and the P21S Soap would be excellent choices for exhaust tips cleaning.