I only ever use steel wool from the hardware store , it is sold here in big hank for French polishing timber fine grade, don't have to worry about nut allergies keeps my pins sharp and clean if I happen to get glue on them , I have had one pin cushion for over 25 years and it is still going strong .

Good idea!!

The rice and the steel wool!!
Good ideas ladies!

I have seen many recommendations in various quilting discussions. I caution against using tree nut shells ground or otherwise. Even the dust from nut shells can put someone into a severe asthmatic crisis or anaphylaxis. You never know if a person with severe allergies will come in contact with the pincushion. Just picking up the pincushion can cause an allergic reaction. Ok so much for my soap box. I use 4-0 steel wool, inexpensive at the hardware store. I wrap the wool with batting so the pincushion remains soft. The steel wool sharpens pins and needles, so having it in the middle is sufficient.

The pincushion I had that had sand in it, the sand kept eking out like fine dust. I cut it open and it was lined with muslin but the sand still eked out.

I have pincushion that was gifted from neighbor. Heavy with steel wool and "bb" pellets for the weight. Really heavy and doesn't move.

I love the steel wool suggestions, I recently tried using fusible fleece to back my pincushion pieces and find it gives a much smoother finish. This would also give some buffer between steel wool and the fabric, going to have to try it soon. Also like the BBs as weight! Love all the great ideas that are shared here!

what to use to stuff pin cushion...
 

Lots of good ideas already listed. My Aunt made me a pin cushion when I was not very old, and she used hair clippings. That has always been my favorite!! Nice and firm, and great memories of her as my Mom's sister.
Mariah

BBs are a great idea.

I put dried beans in the bottom of mine for weight and use the steel wool from the hardware store. I wrap it all in scraps of my ugly fabric then put the pretty fabric on it.