No, I would not suggest using spoiled milk. You can get sick from that. Spoiled milk is full of bad bacteria, not healthy bacteria. You need to start with fresh milk.
Adding vinegar is not going to make that milk safe.
Just because something is on the web or printed doesn't mean it is safe to follow.

This is not "soured" milk like you'd get on the farm. This is rotten milk. The life of most commercial milk has already been extended by ultra-pasteurization, so when it goes bad it goes really bad.

I think you can make excellent fresh cheeses but start with the best milk.

Carol

The vinegar is there to help the milk curdle. You can also use lemon juice to curdle the milk. I agree that you should use fresh milk if you want to make cheese.

Rodney