Actually, I've spent years stretching my own scrotum and testicle cords, as well. Mine will stretch out a long way, but without the actual weight or pull on them, they only hang down about half that far. When warm!
The women I've been with like the slapping. You have to get the right rhytHydromax though, because it can really hurt if they flop too hard.
Just thought you young guys would like to know...
... By the way: Do you think you will lose interest in your genitals or sex in a few years? At what age do you figure you will be finsihed? 30? 40? 50? 60? Do you figure there's an age where you will just say, "go ahead and chop 'em off, 'cause I don't want 'em any more".
Doesn't work that way, guys. If you're lucky, you'll be like the Erergizer Bunny!
(By the way... That's where we have it over the women. Men don't go through menopause and then lose interest in sex. We can perform and enjoy until our dying day!)