via Wikipedia:
Becoming a sadhu is not for everyone. It is supposed to be the fourth phase of a Hindu’s life, after studies, being a father and a pilgrim but for most it’s not a practical option. There are some who fake holy status to gain respect but they are soon found out by any real baba.
Becoming a sadhu is no easy option either. You have to die onto yourself and may be required to attend your own funeral before following a guru for many years. You carry his stuff, you make the fire, you bring the water and so on until you have enough experience under your belt to strike out on your own.
While many dispute whether a Westerner may become a Hindu, he may become a sadhu provided he finds a guru that will accept him.