DH and DSs tried the NoNetz a few years ago and they didn't work out. At the beach they got a ton of sand stuck inside. At splash park type places and anytime they weren't in the water at the pool they were too hot. They all wear suits from Target now and those seem to be comfortable enough.
That said, they were recommended to me by a parent whose son is really sensitive and they work great for him.
DH also occasionally uses anti chafing cream in that area. Maybe that would help.