First of all, I am glad to have joined the forum and have enjoyed reading some of the posts.

I am having trouble with a cat that keeps fouling right next to my house(10cm). To make matters worse there is an air brick vent there - I am sure the smell is travelling into my house.

I have tried cat powder and mothballs, both made no difference. I am thinking of getting a device that sends ultrasonic sound out. It has to run off batteries and be water proof and above all work!

Can anyone provide a link to a device that they have tried and know that it works well?