I have an old sink in the potting shed. I fill this with water and scrub the pots out with an old kitchen pot brush. They are then dropped into a tub of water with a 'good splash (smellable)' of cheap houshold disinfectant from the supermarket. When the tub is full of pots, or the washing session is over, the pots are dumped into a basket (old washing basket/ supermarket tray) and left outside in the sun and wind to dry.