Celestial, I've tinctured Solomon's Seal Root and I love it, so does my husband. I ordered C/S (cut & sifted) so I can't answer your question about the powder.
When you place your next order what you want to get is the C/S, its chopped up into small pieces already so you don't have to worry about breaking down the roots into pieces.
It must have some kind of resin or oil properties because the tincture looks like its oily once its tinctured. I loved shaking it because it looks cool due to the oily look of it, it shakes differently somehow.
You want to tincture it in 100 proof alcohol, you don't use any ACV.