0.45X Wide Angle Multiplier

[Iguanasan]

Just wondering if anyone else has tried this and what was their experience if they did. The widest angle I can get right now is 18mm but if I can turn that into 9mm or even 12mm with this little device and get reasonably good quality images I would be satisfied for the price.

58mm Wide Angle Lens 0.45X For Canon Rebel EOS 18-55mm: Amazon.ca: Electronics

Oh, I should also mention my desire for this device so you know what I want to do with it. I want to be able to shoot house interiors and my 18-55 kit is the widest angle I can get. I'm trying to create reasonably decent images of bedrooms and living rooms to display on the web for rooms for rent. So, this doesn't have to be perfect and if I can get 12mm out of it I think I would be quite happy.