1. Use salad oil on the grater. Prior to grating your vegetables, add some olive, nut or other salad oil to the serrated edge that you will be grating on. This will provide a well-oiled surface that will not interfere with the grating action but will ensure very easy cleaning after the job is done.
2. Wash in warm, soapy water. You can use a toothbrush to clean. A toothbrush reserved for kitchen utensil cleaning is really handy for grater cleaning. In particular, it can remove cheese, onion and citrus rind much more easily than your fingers and there is no need to worry about cutting yourself.
3. Stand on a dish draining board or a space lined with kitchen paper to allow the water to run clear of the grater. It is much easier to let a grater air-dry than to dry it yourself; this avoids the potential for finger grazing and cuts. Alternatively, you might like to place it in a warm oven for 10 minutes.