There is another material called A+B, popular with many sculptors and seen it being worked when Andrea Iotti paid us a visit and made a demo, very good aswell, much finer then milliput.
Milliput is good, I prefer the standard then the white but find the above products much finer for certain detail but not as strong as milliput so what I do is use milliput for the base and work the rest according. This is my way does not mean it is good ... Larruccia who by far is one of the top master sculptor work his models with so much intricate detail ALL in white milliput ... so depends to know your material, learn the properties and experiment!
Magic Sculpt is available from our maltese friends in UK, El Greco Miniatures ... Duro can be purchased locally from Forbidden Power in small strips via GamesWorkshop [green stuff?].
Ask David and Steve aswell to see their views ...
Have more fun ...
Ivan