Hi Michael. As no-one else has replied I think we must all be wondering what wind bushes are. As I put in the sheep bit, do you mean 'whin' which is gorse, ie very spikey with yellow flowers?
I know someone who went to great lengths to plant gorse all around his house, but he lived in the Scottish Western Isles and he thought it would be the only thing which would grow there to form a windbreak.
I love gorse from a distance, on someone else's land

but I can see why you would want to get rid of it on your own. Sorry but I don't know of any special tricks - I would cut it off at ground level and burn the tops, but I don't know how to stop regeneration.