seriously now - it does make a difference, i've done it 3 times - get an old tesco-cheap-water bottle and fill it up, squirt it around your edge of the garden, trees, door/cat flap
your male scent is extremely powerful - your cat already used to it - the other cats think your marking your territory and your female
2 big tom cats used to harrass or female, until i did that, for about a month - then they stop coming and go harrass someone elses cat.
seriously now - it does make a difference, i've done it 3 times - get an old tesco-cheap-water bottle and fill it up, squirt it around your edge of the garden, trees, door/cat flap
your male scent is extremely powerful - your cat already used to it - the other cats think your marking your territory and your female
2 big tom cats used to harrass or female, until i did that, for about a month - then they stop coming and go harrass someone elses cat.