Process is pretty simple, let the seeds and pulp sit in water for a couple days, then rinse and dry. Worth extra effort for the better germination rates!
[Image descriptions: 1st image is of several jars on a kitchen counter containing varying red to yellow shades of goo floating in water. 2nd image is of a wet sieve with tomato seeds over a sink, with an empty jar in the background. 3rd image is of the seeds spread out on numbered paper towels on a kitchen counter.]
I was just thinking about saving some seeds from my sungold tomatoes this year and your post hit at the perfect time. Thanks!