Waterproof
Strongly agree!
Looking back, I suspect this was only an argument to make them hard to repair, as always, just worded in a sense like it'd benefit the customer.
FFS, just add some rubber... We've used rubber in condoms for centuries (kinda) succesfully, what made them think glue'd be better... I ain't gonna put glue on my ding-dong, if that's what they're after all these years.