I didn't need to adopt a new religion, nor even have a religion, nor take up strange practices. (Depsite the dramatic title.) The approach here is a method; Tantra is a method, not a belief. All that was needed was an open mind and the will to try something simple. Osho expresses himself in English very clearly and vigorously, there is no mystical-technical jargon/tedium! If it works for you, there's no strenuous effort! But you may feel like you've lost a backpack of rocks you never knew you carried. It worked for me before I got past 1/4 of the techniques (I read an earlier, partial edition.) It's been 6 years since then, and the benefit has endured and grown - not a flash in the pan. Yhere just aren't words to describe "it," you have to experience it.
Yes, Osho got in big trouble sexually and financially here in the US, but that doesn't mean that the principles he advocated in his books were flawed. Enlightenment isn't always portable. American society is known for its ability to produce trance states more related to materialism than spirituality and this is especially true of immigrants unused to its seductive power. For an amusing look at the impact of Americans going to India in the 60's read Gita Mehta's "Karma Cola".
You certainly can't compare OSHO to someone like the Dali Lama, but the fact that he didn't maintain a lifestyle in keeping with third world spirituality is perhaps his greatest contribution to the American understanding of eastern principles. His was able to write in a clear and concise American style about principles which are antithetical to the American reality. He wrote with a full knowledge and compassion of how seductive life here can be...In this way The Book of Secrets is not just another tome delivered by someone looking down from a position of study and fasting...but a useful life manual delivered from a position of immersion.