I have tried several different ones over the last few years and have had the same luck with all. They all work really good but my time is much more valuable doing other things then polishing my tunnel and thats what I hated..........
Talked to Tim at Bio Kleen and he chated with me about his Sled Brite Line. He is a great guy and a genious when it comes to chemistry. He sells 2 products that work really really good and very fast. First is called Alum Kleen, you spray the tunnel or metal with the Aluma Kleen and let it foam up for 15 seconds to 5 Minutes depending how oxidized the tunnel is. You can speed up the process with a nylon brush and then wipe it clean. Then take a dime sized dab of the Metal Renew and rub in small circles with light pressure and wip clean. Takes all that card scrubbing and rubbing out of polishing and cuts the time by about 80%!!!!!!
The Sled Brite Line has several other products that work very well also. the belly Pan cleaner will just mest that baked on exhaust right off the sled!!!!
Awesome awesome products!!!!!!