Hi Jayzee
here is a fly I have been using this last couple of weeks to represent cowdung flys sitting high on the water. It has been working a treat so might be worth a chuck

.
at the moment up here it is the only the odd one you see blowing past every now and again. Under these circumstances I think it is important to really gink up the fly and get it sitting high on the water upon casting out give it a wee while to fish static before retrieving.
If you watch a "shitey" fly blowing past on the water it has that gingery/greeny colour but a yellow is also promanent and in my mind this should be brought into the tying .
Just a line of thought mate and I hope someone can give you an idea on the merits of a more traditional Cow dung pattern as I havent tryed one for a good few years now and want to know if Im missing out.
The tying of the fly in pic is
Hook size 12 or 14
Dub :Frankie McPhillips Ballinderry olive (im sure anything close will do)
Wing ; Hot olive roe
Cheeks ; yellow goose biots
Thread ;yellow 8/0 uni
The only thing I would add is that I fish this as part of a team of flys as there is not enough cowdungs about to concentrate on one line of attack at the mo.
Jim