How interesting. Never done this jar of water thing before. Although, I have rinsed off some tomato, cantaloupe and honey dew seeds under the tap to get the goo off them. That's what I love about this forum, we can learn from each other. I looked up saving seeds and sure enough, washing the seeds in water before drying is how it's done by serious seed savers (who know what they are doing).
Youy don`t have to do all that with pepper seeds because they are separate from the flesh. Just take them out and dry them on a paper towel.
I personally don`t worry about it. 100% germination is next to impossible. And if I remember correctly since there is no flesh on pepper seeds,,neither are they moist and dense,,almost all should float !! Will check next year.