Crazy idea, how about making non-disparagement clauses illegal?

They serve no purpose, other than protecting abusive and exploitative companies.

If a disgruntled employee says something that is not true, there are already laws the company can use to defend itself and the company has way more resources than an individual. That's enough to deter even people who want to expose the truth but are not confident they can prove it. These clauses just make the power differential even larger.