Yes, someone asking about the device with the button, is the bark repeller. It's by Pet Parade you can locate this from
www.amazon.com or you can read up a few posts someone posted the direct link.
I think I already posted my success with the bark repeller. She still tries to bark on occasion when out on our walks but once I press the button she is instantly quiet. If she even tries to peep that half-bark I will press it again and she understands it's a NO NO.
I never tried the citronella collars or spray bottles because only one thing comes to mind with these is that they could easily ignore them because for one, a lot of dogs LIKE water from hoses etc and would think you are playing with them with the water pistol (this happens with both my sisters in-laws' dogs). The citronella collar is just a bad wiff of a bad smell, right? Or am I thinking of another kind? Either way, especially outside, the smell could go away in a snap if it's windy, right?
With the bark repeller controller, as others have said you have full control. No painful collars on your dog (not to mention many of us already have ID collars on our dogs plus harness' for the lead so a third collar would be entirely too much) and no weird smells.
For any who are not sure, what the bark repeller does is emit an annoying sound that only dogs can hear (so if you are within a few feet of other dogs you may not want to use this as other dog owners may not appreciate or the other dog may not need the "punishment"). As far as I know it is not a sound that would be detrimental to your dogs ears in any way. Some high frequency sounds in the past I was able to hear from other devices (its been like 6 years since I've owned any dogs), but this device I cannot hear at all.