Why don't people with locks like to shampoo? I have clients, who shall remain nameless, that simply refuse to shampoo for months at a time. I have to shampoo my hair at least once a week. I just can't think of anything on your body that should go any longer than that without a little water hitting it.
I must admit that I am not a stickler for neatly maintained locks. I may tighten mine every 2-3 months. In the summer I definitely wait about 3 months, but I shampoo. We take the whole notion of freedom a little too far sometimes when it comes to being natural. If you can smell your hair, so can other people. If you work out, at least walk past some water every two weeks or so.
Water is your friend.