ArtMetal

My copper tree's coming along now - taking much longer than I'd hoped, but as long as it looks good, and I've learned something along the way that's fine, and I'l know what to charge next time.
I was aiming to patinate the copper with Liberon Tourmaline brown, which I've used in the past on smaller items, but I've just discovered that the health and safety nazis have caused it to be dicontinued.
I know a lot of you guys use liver of sulphur - which I've never used - is it suitable for a large scale piece - and how much might I need ? Can I dab it on with a brush or cotton wool? Someone's selling it on ebay in 10gramme pots- doesnt sound like much, but I understand you dissolve it in a good deal of water to use it ?
I'm hoping to give the tree a fairly even coloration that'll blend in the welds/ bits that have been ground, then maybe rub it down lightly to highlight the texture.