No way colo I always do mine in water... 12-24 hours... sinking has nothing to do with whether they'll germ or not. you can definitely soak'em too long and decrease the viability, but up to 24 hours definitely fine - if they drown in that time there was something wrong with the seed.
not sure where your sparkle seeds came from, but i've definitely noticed the seeds i've gotten sent via mail or through associates here from individual breeders don't germ at as high a rate as my tga beans... it could just be the beans you popped weren't ever meant to be too
i always make sure as soon as mine come out of water and go into soil now they have light overhead... i had one time that i left the beans in the dark in soil for a day or two and i think all or almost all of those failed. Not sure if the dark had anything to do with it or it was just some other factor like too much humidity, not enough, whatever either... but i've had much better results since then making sure they have light over them.
my guess is just unlucky beans though if you didn't even get taproots.