Hygiene (àrogyavijjà) is the practice of keeping oneself and one's immediate environment clean so as to avoid sickness. The Buddha criticised those ascetics who believed that neglecting the body either by eating filth, not washing or not cutting the hair could somehow lead to holiness, a belief that was as widespread in ancient India as it was in early and medieval Christendom. He said: `Not nakedness nor matted hair, not mud nor fasting, not lying on the ground, being unwashed or squatting on the heels will purify one who has not passed beyond doubt' (Dhp.141). He required his monks and nuns to wash and shave regularly and to keep their clothes clean. He said: `And how is a dirty body washed in the proper way? By means of a scraper, soap powder, water and having a good scrub'(A.I,207). The Buddha even gave advice on dental hygiene: `There are five advantages of using a tooth brush. What five? The eyes become bright, the breath becomes pleasant, the sinuses are cleansed, phlegm and mucus do not get in one's food and one enjoys one's food'(A.III,250). See Sauna and Toilets.