Clleaning a Laundry basin sink

Well they tend to have problems with stains. You don't use sand paper to clean them In fact if you have used many commercial cleaners, the gritty ones, you likely have damaged it and contributed to the problem.

Frankly I doubt if you are going to get the stains out. It's a laundry sink, think of it as a patina which in future years will bring back memories of all the good times.

Had the same problem. Went to Home Depot and bought another laundry sink for $39 and replaced the old one.

Try simple green full strength, with an plastic scrubber. If it works it will take several sessions

I am no expert at house cleaning, but I just cleaned my laundry tub the other day. I used TPS (Trisodium phosphate) bought at Rona for $1.50 (in Canada). Home Depot may something similar. It cleans the tub well. I also used it to clean my deck.