I use the Amaco brand called Marblex which is a self-hardening clay. My
kinders make pinch pots and my first graders make a pinch pot with a slab
added which makes a small vase. It works well and I think your individuals
would like it. Keep the balls small enough to fit inside their palms.
When dry we paint it with cheap acrylic from Walmart and then, if they
choose, I coat it with Acrylic Glitter Glaze (Dick Blick) which they LOVE!
I love Sculpey too-Eberhard Faber makes a variation called Fimo Soft but you
might have to order it -has anyone seen the softer kind at Michaels etc?