When I worked in a restaurant the stainless sinks were cleaned with comet and steel wool and then rinsed and dryer with cotton towels to remove anything left. The towels always end up with a grey residue which I believe us steel wool and some of the sink. Bon ami does a pretty good job too.

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95 E300D gave away
77 300D, 227k, station car
83 300CD 370k, body gone away to the rust gods, engine is in a Yota pickup, going strong
89 190E 2.6- 335k, no more
79 VW FI Bus- 154k summer driver
59 VW Beetle ragtop- 175k
12 VW Jetta- 250k
74 MG Midget-78k