What have everyone's experiences been like with the citronella collar when using it for barking?

I'm going to my daughter's in July and she's in a new townhouse....she's afraid the dogs will bark and upset the neighbors.  So, I need to know how much training is required to use the citronella collars...... and if they work.

I had never heard of these. Here's  a link I found. Sounds interesting.

http://www.news.cornell.edu/Chronicle/96/6.6.96/barking.html

Hey Mary Beth,

No training at all and they work great!  I bought 3 several years ago off ebay for about $65.00 each.  The thing is, they say not to leave them on for extended periods of time...

Apparently they can get used to the citronella spray if left on too long. I would only have them on them when we were out somewhere and the dogs were alone...which wouldn't be more than a couple of hours.

I've used it on two dogs and each had a very different reaction to it. 

First dog...one of our personal dogs who has always been a barker when left home alone.  First squirt from the citronella collar and he's pretty much quiet.  When I put the collar on him, he knows he should be quiet.  But, sometimes hearing us returning home is too much for him and he'll let out a bark or two.

Second dog...a foster who has separation anxiety and barks his head off.  The collar slowed down his barking, but in the 1 1/2 hours that I'm gone in the afternoon, he empties the collar (booklet said it has 25 squirts on a full tank).  So apparently the spray doesn't have much of an affect on him.  At least him must think that barking is worth the spritz.

Debbie