Bark ccontrol

Does anyone know if those room bark control devices like this one:

http://www.ultimatebarkcontrol.com/

or

http://www.securepets.com/pbc1000.html

Are they effective? We will be moving in the near future and I some of the nice places we are looking at are duplexes, We don't want the dogs barking if we are gone, if they do, to bother the neighboughs. And we are not a huge fan of the no bark collars.
Nicole

I don't know anyone that has tried them but I would be very interested too!

I don't know how well they do or don't work but on the first one with such a long range (it says it can help with neighbor dog barking), I'd be worried that someone else's barking dog would be triggering it and your dogs would get the "correction" (which is the unpleasant high pitched sound) for their barking.

good point. Something to think about. So I wonder if there is range controls on them? If There is that would solve that problem. I only want it for indoor use.
Nicole