I have used a SOS pad dipped in water to clean all the junk of the exhaust. It requires a little bit of scrubbing to work up a lather. It cleans and also shines it up a bit. I then use a metal polish that says it will polish stainless steel to finish the job. My tailpipes are high grade and the rest is mild stainless if that sounds right but I always used the same technique on the whole system. Windex or any glass cleaner will work in between polishing.