I have saved tomato seeds in the method you’ve described, and it works well. Another method I’ve tried is covering the seeds in an equal amount of Comet and stir. Let them sit for 30 minutes, then rinse thoroughly in strainer. Return seeds to water, and discard the seeds that float to the top. Strain, and let dry on waxed paper. This method is supposed to dissolve the gel and disinfect. Of course, I try hard not to use harsh chemicals on my tomato plants, so I don’t know if this is counter-productive. I kind of like the idea of the Comet disinfecting any plant diseases though.
I did this with a couple varieties last year. I think I did a germination test to make sure it didn’t kill the seeds, but I will do another one with my first batch to make sure, and report my results. I have had a few ripe Tiger Tom tomatoes and Chadwick Cherry, along with one huge White Snowball tomato!
Ditto...plants grown from last year's saved seeds are flourishing, and setting loads of fruit. This is the year where I am going to be taught how to enjoy a tomato sandwich in a pita pocket.