See also Polishing Aluminum and Stainless Steel in the Sportsterpedia.
Here is a very useful link from the Caswell Inc. site. An Introduction to Buffing and Polishing
Download their free PDF “The Buff Book”.
Lots of good explanations there on polishing compounds.

Home made polishing compound from jeweler's rouge, mineral oil and used soap bars. ¹⁾
Finished paste below was placed in an old cut down coffee can.