Sand and shot?

Blu-tack = Audio duct tape

I used generic bluetack on my B&W805s stands.
I made it super thin by kneading it with my fingers until them bled!
1/32 inch thick (any thinner and it 'tears')
The sound without, and screwed to base was too 'tight' in the bass and a bit bass shy.
With the bluetack substitute the bass came out just enough to be perfect!
The generic worked for me... just remember to knead it a LOT before using it. The more the better.. (keep pulling it in to a long strip then fold, repeat. after a dozen strech and folds, twist it up about 30 twists, real tight. then repeat streching and folding. then roll it up into a ball or tube and use it anyway you want.
Makes the stuff much much better.

I had no luck find blu tack at Walmart. Elizabeth where can I find the generic blu tack you mentioned? My quest continues.

Try something else. In my experience lead destroyed much of the microdynamics of the music, especially at lower volumes. Sand much less so, but created some resonance issues. I took a hint from the AudioPoints folks and tried fine metal shot (blasting shot off ebay). Sounded very exciting and energetic, but a bt unnatural. A 50:50 mix of steel shot and sand was just the ticked to retain microdynamics but still sound natural.

I also don't like what high mass does to the sound of my bookshelf speakers, and I didn't like the effect of blue tac, but those are lengthy topics by themselves.

Try these things for yourself.

Elizabeth, the generics that I've used are more sticky, tacky, and pliable than Blu-tack. They are also harder to remove, and when exposed to higher temperatures [car interiors] they will deteriorate to a consistency slightly less sticky than used chewing gum! What generic brand are you using? Maybe I'll give it another try.