We used it to stop Ebba jumping up att people and to stop her from counter surfing. We only had to do it a couple of times and she hasn't done either since! This was when she was about 3 months, and she's 10 now (months). Just make sure you read the instructions, if you use it the wrong way and at the wrong time it can do more harm than good.
Thanks for the feedback so far. We have used the spray water bottle before but are now to a point where Mac just thinks it is a game. So he gets excited and wants to continue the bad behavior but gets even more intense.
I've used a squirt bottle (totally worked) and also compressed air (the type you'd use on your keyboard) also a success.
If you use it once and it works, you're good, otherwise, as some have pointed out, they think it's a game. For e.g. we tried a can of pennies and guess what - we got the "You're kidding, right? SO not scary!".
Also - I've tried to limit the squirting - if I do it too often, he might get used to it and then it will be ineffective.
I have found that the compressed air works best for redirecting attention-- for example, if you're outside and your dog is compleeetely distracted, the noise that the air makes will make the dog look at you and you have about 1 second to issue your command. I also take it religiously to the dog park in case my dog is getting rowdy and not listening to my command.
At 15 wks, I think your best bet is less correction, more instruction. Tell your puppy what you want him to do before he decides to do it. If he looks like he's about to jump, ask him to sit right before he tries. Use the crate as your reset button when he's getting out of control. Calmly place him in there for a few minutes. Others have had good responses from cutting off social contact for just a few minutes at a time. When he does go for something you don't want him to be in, just keep redirecting and praising as soon as he shows attention toward the redirected item. If you're fair and consistent about your rules, most of these things will fade away with time. It doesn't feel like they ever will, but he's doing it because he's a puppy, it's fun, and they don't fully know how to please you just yet. Keep praising and reinforcing ANY and ALL polite behavior and the good behaviors will become more and more frequent.
Agree with Laurita. At 15 wks, consistent, clear correction is best (albeit sometimes frustrating ; however, spray bottles & compressed air can be used successfully for certain situations & dogs. What one dog thinks is a joke, another pup takes seriously. Compressed air works as a distractor for us not a corrector. We use it sparingly & only tried it when I was sure Pumpkin understood the command (in our case "off" for jumping). Jumping is the only time we have or will use it. It should not be a multi-purpose corrector, IMO, especially with a pup. Like all tools with smart Vs, they are keenly aware of when said tool is in their presence. P can look at a can of compressed air & will not jump. No sign of compressed air, and she probably will try. Practically speaking, you will not/can not have a can with you all the time; therefore, consistent training is always best, IMO. It has longer term results. Good Luck.