Startup Idea: Automated Git Repositories Cleaner

Startup idea to develop a software that can efficiently clean up local Git repositories, removing unnecessary branches and deleting irrelevant information, thus helping to keep the repositories well-managed and saving the time of programmers.

I am a programmer on several open-source projects that use Git and Github as our Version Control Software. Over time, local Git repositories (that is, the copy of the code stored on our home computers) can become a mess if not properly managed. A piece of software that can clean out a Git repo by removing unneeded branches, deleting information that is no longer relevant, etc. could be quite helpful. At the moment, all we can do is manage this manually, which takes a significant amount of time. There are no tools available that can perform this sort of mass-cleaning easily that I know of.