Precassino mill had a grindstone and a husker with a double mortar. The first was used to make flour, particularly cornflour for polenta. The second, which was older and has now been reconstructed inside the mill, was used for husking, removing the husks from the grains of barley.
Find a small stream and take a cork, two pins and four disposable spoons (preferably made from compostable material) with you. Stick the pins into the ends of the cork. Then take the four spoons and use a cutter to make some incisions in the cork around 90 degrees apart from one another. Insert the spoons into the cuts. They will act as the blades.
Look for two forked twigs and stick them into the stream bed so that they protrude up out of the water by slightly less than the height of a spoon. The distance between them should be slightly greater than the width of the cork. Place the pins in the forks and the wheel will start turning, driven by the current.