Sand or Lead shot

I haven't seen lead shot available in stores. Only steel shot. This is what I have used for quite some time. I think it works very well. It's not as messy as sand. Don't have to worry about it collecting moisture like sand can.

A few comments: Sand doesn't collect moisture if it starts out dry and is in a sealed enclosure. Lead is not a health hazard unless ingested. IMO, though, sand is just fine for most damping applications. The only benefit of lead or steel is increased mass, which can be helpful but isn't always.

To my knowledge, all lead shot sold in the U.S. is plated with Bismuth. The risk of toxicity is minimal. Lead is most toxic when it is part of compound that can easily be absorbed by the body, such as tetraethyl lead that was once used in gasoline. The metallic form is very poorly absorbed by the body, but be cautious not to inhale any powder or fumes from molten metal. You should get the smallest size shot you can. Buy it at a gun store that sells reloading supplies.

I endorse the use of the microfil from star sound. I have their sistrum stands with this and it makes quite a difference.

For speaker stands, it is not that critical, but for component stands, using a non-magnetic material would be a better choice. Magnetic steel has caused some strange reactions for me with my VAC 30/30 Mk. V Signature tube amp.
I purchased an attractive, manufactured steel posted stand
a while ago, and after placing my amp on the bottom shelf and listening to the system, I was shocked to hear how horrible things sounded. I had changed nothing but the stand, and it suddenly sounded worse than I could ever imagine...VERY muddy and ill-defined! I had to re-assure what I was hearing was real, so I invited several others to confirm...They agreed it sounded horrible. I then removed the rack and tried again. Back to normal like it should be!
To be on the safe side, use stainless steel, aluminum, or wood for your support pillars on stands, especially if they are close to the transformers.