Honestly, I hate those things. The water-based ones are bad enough. Citronella is even worse because what is a pleasant smell to us is likely awfully strong for a nose so sensitive that it can detect half a teaspoon of sugar diluted in an olympic-sized pool!
All no-bark collars rely on simple punishment, which comes with significant risks. I have personally seen dogs grow terrified of the spray. In one case a formerly playful dachshund switched to exclusively lying under the kitchen table, shaking uncontrollably at any of the sounds that used to make him bark. A fellow dog trainer also told me of a case where a terrier resorted to biting visitors. He had previously barked, but kept his distance. When that option no longer seemed feasible (because it got him sprayed), he charged.
Any reason you are not considering positive reinforcement? Have you tried that already, or is the barking happening when you are not around?