My over 30 years old laminate kitchen countertop had accumulated a lot of marks over the years that no cleaner would remove. I finally gave up and decided to use chlorine bleach on it knowing that the bleach may damage it. The bleach removed all the marks — looked like new.
There is only one unfortunate side effect: iron objects, e.g. cast iron, that come into contact with the countertop leave permanent black marks even a year after bleaching. I suspect that the bleach damaged the seal on the countertop since I doubt any chemical residue from the bleaching would remain after a year. On the other hand how could an over 30 year laminate countertop still have any kind of seal?
Any idea how I can prevent the black marks from iron objects?