I cut up a notch in the top of a roll of expired 35mm and then in the dark, unrolled it to the end, then taped it to a marker cap, rerolled it and jammed it into my square format childhood camera, a Kodak Instamatic X-35F. I knew it would leak but I wanted it to some, but I did tape one side that I was able to to see obvious light through. After each shot, I twice wound the camera and fired off the shutter with the lens held against my arm. This was necessary to have the film advance enough to not overlap too much.
Scanned on my modified Epson V300.