My upstate NY porch floor was built with stone quarried from northern PA. The previous owner got some white paint drips on it which I would like to remove. What I've tried so far:
Sealkrete Clean-N-Etch concrete 2-in-1 cleaner & etcher
Neither of these made ANY difference whatsoever. I even tried the Sealkrete undiluted.
The only other thing I can think of is straight muriatic acid.