I have been working with Fuji FP-100c45 negatives lately. I am ecstatic to have found out about this tecnique, since the Polaroid 55 and 665 packs are beyond expensive. I do have a stock of Polaroid 665 in my fridge, but I do not want to use it except for my next book that I put together.
1. Take your photo, and overexpose it by 1-1.5 stops. This will make the negative the proper exposure, but overexpose the print. Then, when you pull it from the camera, do not peel it.
2. Tape the photo, negative (black) side up to a piece of glass. Then, brush undiluted bleach onto the black backing, being careful not to let it leak under the photo.
3. Rinse thoroughly with water until all of the black backing has been removed.
4. Peel the photo from the negative.
5. Rinse the negative again until it is clean.
6. Dip into water/photo-flo mixture and then hang to dry.
Once dry, it is like any other negative and can be scanned or printed as such. I used a color negative in the example, but you can also use Fuji FP-100b. This method only works for the 100 speed, and does not work for Fuji FP-3000.