There's ton of stuff that is good for hair such as vitamins, minerals, collagen, probiotics, etc. It doesn't mean you'll regrow any hair which was lost through male pattern baldness. It's quite safe to assume at this point that castor oil applied topically on its own won't regrow much hair, if any at all. And that's based on more than two decades of experience from people using castor oil for this purpose. Maybe if the manner it's applied on changes, it could turn out to be an effective treatment. Anyways, peppermint oil atleast has a scientific study behind it, although done on mice, where it works more effectively than Minoxidil.
Again, you don't know what you're talking about. The only reason castor oil won't work on its own (topically) is bc it's 933 Daltons. Thus why it's mixed with DMSO or taken orally. PGE2 has been scientifically shown to be lacking in balding scalp and a number of PGE2 analogues and agonists have been researched and shown to help regrow lost hair.
Meanwhile you're leaning on a mouse study for peppermint oil--which has actually been proven to reduce PGE2...