eChipmunks - Has anybody used those electronic pest controls that plug into your wall and if so, do they really work?

Has anybody used those electronic pest controls that plug into your wall and if so, do they really work?

It is advertised to get rid of roaches, rats, and mice.

i have been using one for the past year. a few days before i plugged it in i was seeing 4-5 cockroaches a week (i live in an area where cockroaches are everywhere even if you have the cleanest house! ) after i plugged it in, it went down to 1-2 a week. after about 2 weeks, i stopped seeing them all together. i can let you know once the weather starts warming up again if they start to show up, but i honestly haven't seen one in sooo long. so in my opinion, yes, they work. email if you have any more questions! :-)
I have used one for years and have not seen any roaches. This device has a high frequency sound that is adjustable and as far as I am concerned, it does the job. One other note, it does not work to get rid of ants.