Thanks for sharing this tool!
PolicyCleanUp is very useful, but it's worth mentioning that it only deals with cleaning up "un-hit" rules.
If you want to really tighten your policy, you might still have many rules that include un-hit objects or very wide networks or groups that only a small subset of them are in use.
Policy Insights (GA for a while now on R81.20 and above) will help you do a deep clean with prioritized recommendations for un-hit rules, un-hit objects and overly permissive groups / networks. It will even give some recommendations for group reuse to make your policy more readable.
Definitely worth trying it out.