Bang and the dirt is gone

[diredesire]

I think the reason people don't use more highly acidic substances is because the damage they do to the blocks. For e.g cilit bang is highly acidic for a domestic product and leaving it on any surface for more than 5 minutes can cause pretty bad damage, I left it on my block for a few minutes and it left marks. My next step is fizzy cola but considering leaving it in ketchup overnight (that will sort out the vinegar dilemma as well)

I would hardly qualify vinegar as "highly acidic," if anything, it would be less "risky" to try as an experiment compared to coke/ketchup simply because it is more "pure" in my eyes, nitric acid and water versus tomato pastes, spices, etc. I'd give it a shot, you've got nothing to lose, really...