Hardcoated pipes?
#18
However, the first time I tried this method, I used 50/50 premix. The pipe actually turned black. But I really like it, it looks like black chrome
#19
Tech Regular
#22
DAWN power dissolver, the best product next to the now gone CHEVERON PERFECT ENGINE CLEANER, give it a try, 30 minutes is all it takes and leaves your pipe and engine brand new!!!