I have given Holly very diluted freshly squeezed oj twice (when she was super constipated).
She loves drinking water, absolutely guzzles it from her doidy cup or bottle, so I figure while she's happy with that, stick with it.
It's much better for them to eat the actual fruit rather than have the juice - that way they get the fibre etc.
I also have a serious issue with 'Fruit Shoots' and the like. Just so much sugar in them. When I was a baby, my mum let me have lots of Ribena. It rotted my two front teeth, which means I then had to have all four front teeth taken out in one go to stop it spreading.