One common cure for dirty pennies is to put them in vinegar and salt. The vinegar should react with the copper oxide on the penny in the following way:

$\ce{2CH3COOH + CuO -> (CH3COO)2Cu + H2O}$

Nurdrage, on YouTube, did a video on it, and he did say that salt speeds up the reaction. However, he did not mention the way in which it sped up the reaction.

The same exact question is here

However, the answers did conflict and there was no clear correct answer. I am re-asking the question, in hope of getting a clear(er) answer.