Bronze, being a marine alloy, would be better than brass. I do know that the brass swivel, snap shackles are superior to the chrome plated steel ones.
Our Lab used to love to go beyond the breakers to retrieve, our Lab/Chesapeake/?? Mix is happier to stay just short of the breakers.
The easy digging in the sand? ....Happy Campers.
I have no idea why he makes that mistake in his pitch to sell them.
The *old* video bragged on the bronze and was part of the reason I dropped the cash for it.
The leads -do- have bronze snaps.
The other training leads I have with brass snaps are nothing to brag about.
[except for the Jaeger lead]
Cheap Chinese crap turns green and gets cruddy looking in incredibly short order.
It’s hard to find the old good “red” brass anymore..it’s all the cheaper, substandard ‘green’ stuff, now.