Don't leave oils directly on your scalp if your hair quickly becomes greasy or you have dandruff. In that case you already produce a lot of sebum and adding more will make it worse. Especially if you have dandruff, the fungus feeds on oils and becomes more aggressive in that environment.
If you have a dry scalp and dry hair at the roots, you can rub oil into your scalp but pick lightweight seed and herbal oils that absorb/evaporate quickly. A little goes a long way. Heavy oils (like soy or other cooking oils) on your scalp will just sit there and become uncomfortable after a while.
I love bread.
Cause everyone is unique and special. :D
The braching advice is just to make sure there isn't a one-size-fits-all mentality. Listening to your body trumps AI review websites and advertising. The real gist of my point is if someone else uses a thing that works great for them but makes you itchy, choose to not be itchy. If it makes their hair lovely and wavy but yours feels heavy and wet, choose to not feel heavy and wet. There's nothing wrong with experimenting to figure out how your body reacts to its environment. When it comes to your body, you're in the driver's seat.