hold the secret for/of

[angliholic]

The new formula holds the secret for/of beauty. Try it for two weeks and you'll see the difference of your skin.


I wonder if both for and of fit in the above context. If yes, are they the same in meaning? Thanks.

[Soup]

...holds the secret of beauty ~ holds beauty's secret
...holds the secret for beauty ~ for the prupose of becoming beautiful
...holds the secret to beauty ~ towards becoming beautiful

[angliholic]

...holds the secret of beauty ~ holds beauty's secret
...holds the secret for beauty ~ for the prupose of becoming beautiful
...holds the secret to beauty ~ towards becoming beautiful

You're as sharp as what you were! Soup.
Well put! Thanks.

[angliholic]

Suddenly, it crossed my mind that I wrote something wrong.
Correction:
You're as sharp as you were!

[Soup]

Both are OK and they mean the same thing:

You are as sharp as what you were ~ what you used to be.
You are as sharp as you were ~ as sharp as you were before.

[angliholic]

Hammer on! Soup.
Sharp analysis as usual! You're really awesome!