Lakelady, I never but never use a sieve when processing seeds from fermenation, but never.
Unless you read Craig's blog at his website, and I don't know if he even has his fermentation method there I don't think it was his method you read b'c for many years now he's posted only here at Tville.
perhaps you read my seed saving method from my book which isn't all that different from what many do, but it did have pictures and detailed descriptions.
But no sieves, never sieves for me when I process seeds.
And after growing about 3000 plus tomato varieties and setting up fermentations I'm pretty proficient in my dotage, humble though I am.