Tesco Tea-tree shampoo at 60p a bottle is brill. Have also used gallop for black horses which I think worked - anyhow gave me purple hands for 2 days! Also a power washer is v effective too if your horse doesn't mind!
Well Folks, it seems i'll be dabbling with Tesco Tea Tree. Or Asda's own.
I did once use Pantene Pro V 2in1 on the last horse and although he smelt utterly divine, he did smell like a tarts handbag and I was worried he'd get picked on in the field by the others boys!!!