Castrol is Castrol and castor is castor but Castrol is not necessarily castor.

Castrol is a brand-name for a wide range of oils made by Castrol UK.

Castor oil is the name of the oil extracted from the castor bean.

And not all castor oils are made equal.

It's important to use a degummed castor oil in model engines or they'll soon wind up covered in a thick sticky tar-like varnish that will rob them of performance and may even stop them from running.

I don't know if castor made for the cosmetic industry would be degummed or not.