The build up was so good on here i had to try it...
I Wire brushed by hand and with a drill the bottom of my doors...03 Ford F250 SD.
I clean all i could, all that was left was very pitted metal I though this would clean that up, Wiped it all down with Pre Perp New Shop Rags and applied the gel with a form brush, Kept it wet for Hour...
By Morning all i got was a yellow green slim Tried to clean off with water as it saids on the bottle,than soap and water, Then almost the whole bottle pre prep. Called Eastwoods tech help line. was told to sand it and use lacquer thinner, OMG sanding didn't work too taactie lacquer thinner got it off and rubbing it forever ... Live and learn......
If it sounds to good to be True walk away...