This method comes from one of my teachers, Dr. Aryeh Cohen. It’s intended to work in concert with his ketubah, which has explicit egalitarian conditions (tnaiim) built in that are based on some texts found in the Cairo Geniza. His ketubah text is online here.
His kiddushin formula is to work as follows: Under the chuppah, the bride first gives a ring to the groom with the declaration, “Harei atah mikudesh li…” (Behold, you are set apart for me according to he laws of Moses and Israel) and then the groom gives a ring to the bride with the same declaration in the feminine form. Cohen follows the opinion of many poskim that such a direct parallel between male and female actions–particualrly when the bride makes the declaration first–effectively obviates the kiddushin, and the kinyan is not maintained. He writes,
The ring exchange obviates the possibility that there is kinyan in the kiddushin formula and then all that is left in the formula is the statement of dedication to each other. This semantic option is already present in the gemara (de-asar a-kula alma kehekdesh) (and implicitly in the mishnah beginning of the second perek). So
I would say that the kiddushin are valid though not a kinyan (or to my mind valid and not a kinyan….
This act of deliberate subversion enables the bride and groom both to exchange rings with the traditional language in an egalitarian manner and to avoid the ethical problem of the male acquiring the female altogether. In this formulation, there is no kosher kinyan, and yet the presence of seven blessings and, just as importantly, the specification in the ketubah that the dissolution of the marriage requires a get mitigates accusation that the marriage, being safek kinyan, is not kosher and/or does not require a get in the event of its dissolution.
This solution is very close in external form to R. David Mivasair’s method, but with an entirely different underlying intent and understanding of what’s happening. Rather than attempting to effect kinyan through an act that’s not regarded as viable to many rabbis (that is, saying an identical formula and exchanging identical rings), Dr. Cohen embraces the possibility that the kinyan may cancel itself out through equal exchange, and uses it to his advantage.
Safek kiddushin–a marriage about which there is some question as to whether or not kosher kiddushin has occurred–is understood to require a get l’hatchila (at the outset) but not b’deiavad (after the fact; if, say, the marriage breaks up and the bride marries someone else, her second marriage holds even if there’s been no get). There is some debate about whether a wedding that intends to be safek kiddushin can really count as such.
ADVANTAGES: Nobody gets bought, the traditional form of kiddushin is maintained, the couple is sufficiently married to require a get while avoiding the classical issues of get requirements.
DISADVANTAGES: There’s some safek about safek kiddushin.