Drill+ steel brush attachment+autosol and plenty of patience gets the tips clean.
The wire wool pads work quite well too if the carbon is really baked on.
Drill+ steel brush attachment+autosol and plenty of patience gets the tips clean.
The wire wool pads work quite well too if the carbon is really baked on.
The stainless tips on my RX8 were black when I got it, and with a lot of elbow grease on the left, and a machine polisher on the right, it took 15 minutes of hard work with a cloth on the left and a couple of minutes on the right with the mop to get them to mirror finished.
Don't use anything abrasive like wire brush, you'll just scratch them. You want the chemicals to do the work.