I was somewhat reluctant ( I was specifically asked to keep this between "you and me" ) to post but I am curious as well. My urologist brought this up with me during my last consultation, the method concerning harvesting buccal mucosa from the cheek. As far as I know they harvest this tissue and cultivate it for several weeks before using it for the surgery. Of course I am at full trust with this urologist, especially considering he has an extensive history of reconstructing genitals in sexually ambiguous persons.
As of now I am not sure the entirety of the specific details, it was brought up to me as somewhat of a surprise to me by my doctor who alerted that it was something he would highly suggest. I should be able to offer more details after my second consultation with the urologist and the plastic surgeon he works closely with.
Any information would be wonderful since google seems to be elusive about this "experimental" method.
To add just a tiny bit, my urologist said that dilating is only done for about a month or so with this method. Also it is not as sensitive as with the penile-inversion techniques, yet there is far more tissue/material to work with to create an aesthetically pleasing, functional vagina. The trade-off is that you may be somewhat insensitive ( regarding pleasure ) to penetration however have a usable clitoris.