I am interested as well... We are renovating a farmhouse with acreage and living elsewhere (neighborhood with large lots....roosters "allowed", but there is a noise ordinance... - at least that is my understanding.) This is a temporary situation.... We have chickens at both locations, with crowing roosters generally moved to the farmhouse, but for various reasons we have a "crower" at the house in the neighborhood. Our temporary solution is to bring him in at night (dog crate in laundry room). He rarely crows during the day, and the neighbors do not mind, as it is infrequent and we have large lots.... But if he was bothered at night, and crowed... People would be unhappy. With that said, we are very quiet and careful if we get up for a drink of water... and he has been known to crow for "unknown reasons" indoors in the middle of the night.
If the collar works and is safe and humane, we would be interested....