I used bio powder. Bi carbonate power. Bleach and that did t work

So I then used viniger neat left it hr an hour then washed down with flash with fabreeze and it worked

ATD.

I use this - it's brilliant!

http://www.bactonature.com/odoureliminator.html

I hate the smell of bleach so mix in Daz liquid to do my patio. In warm weather I find the gullies stink 'cos some of the dogs wee directly over them (helpful) so after power washing everything down I make up a watering can full of zoflora which smells nice for ages. Sorry I can't help about the grass problem.