I'm not sure I'd put a bark collar on a 7mth old, but I that's your choice.
I use a bark collar on my male aussie. I kinda pride myself on being a pretty good trainer, but this dog does not shut up
He barks at nothing sometimes, most times it's critters, people walking by, people coming to the house. He barks himself into a 'frenzy' and goes into the 'zone' I call it, and then that pushes him into redirected agression usually towards my other aussie..
Nothing worked, I decided to try a bark collar, and ohhhh it works
) I got one at Walmart, (not hugely expensive, didn't want to spend alot of money if it didn't work!)
Anyhow, he loves the darn thing, if I get it out, he comes wiggling right up to put it on..(he's a weird dog!),,it has 3 settings..the first is an alert bing, if he doesn't stop within 15 seconds, he gets a low jolt, if he doesn't stop after that, 15 seconds the jolt is a little stronger, and so on for the 3rd time.
I swear when he has it on, he does NOT bark at all, (my husband tried it, and said it's really not a "jolt" more of a little zing to snap him out of it)...in fact, he's calmer with it on, doesn't go into his "zone of no return"..
I do NOT leave it on him unattended, and I would never suggest anyone do so.
So hey, it works for my aussie anyhow