Well, since YOU brought it up-- NOBODY has advocated the "rhythm method" since at least the late 1970's. You may be confusing it with Natural Family Planning, which has been proven to have an effectiveness rate of 99%. More info here:
http://ccli.org/nfp/
As for "condoms interfer[ing] with the natural order," that's a little hard to deny unless you have a condom growing out of your body.
You can find plenty of people defending it with a simple google search.
Example: "rhythm method" site:freerepublic.com
And nothing man does interferes with the natural order. We and everything we do and create are part of the natural order.