The map and location notes on that link are somewhat confusing.
The cave is in Hall Dale, just off Dovedale. You can park in the village of stanshope, about 15mins walk away. Unfortunatly the cave is quite hidden so I will knock up an approach map.dan
I usually park in Stanshope, and then follow the path into Hall Dale through a couple of fields. Once over the last wall, I turn left and go up the steep slope formed by the side of the valley, right to the top by the wall. Now follow the wall along (passing two gates) to where a short barbed wire fence leaves the wall, and goes diagonally towards you, down the hill. Walk between the end of this and a small rocky knoll, heading down the hill. The cave is pretty much directly beneath this knoll - just where the bushes and trees start.When at the cave, you can get down to the main path again by going straight down the steep scree bank (This might form an easier approach when you know exactly where to go up) - but I prefer to go back the same way.
Conditions are still a mystery I think, as it was only discovered this summer - so whether it seeps or not (and when it is best to climb) has not yet been tested. (woz) may correct me, but I think it was dry all summer long - may even be dry now, who knows?