Swish the playpen round in a bathtub to create agitation. Agitating the playpen will ensure water flushes through the fabric removing grime. Drain the water and check for stained places, then use a soft bruised brush and scrub it. After scrubbing, you can rinse the playpen with cold water. A simple way would be to use a detachable showerhead to rinse. If it is not possible, take it outside and use a hose. Lastly, towel dry to remove excess water and ensure the locks and hinges are as dry as possible before taking it outside to air dry.