We sliced a bunch of branches and dumped them into a plastic tote thinking they would be fun manipulatives for the children in our family child care program. We were right.
The children love to drive cars through them, pour them from one cup to another, load them into purses and boxes, paint them, mix them into play dough, glue them together or to other things, and dig in them. We named them Little Logs and you can order them by the gallon (which will fill a medium sized plastic tote a few inches deep).
You could cut them yourself if you like, but it takes a long time to fill a gallon bucket if you’re doing it by hand.