I took yesterday a guagua from Samana-City to parada Senderola La Javilla, 70 peso, you can tell the driver to stop there at the sign for the parada. Then a nice 35 min walk in shadow, hardly ups and downs, didn't even get my shoes dirty. All the time straight forward, can't miss the way. After 10 min there is a branch to the right, don't take that. In another 5 min a branch to the left over a river, don't take that. Above the waterfall the stairs down are on the right side of the building. For the way back I took the normal way. Was also a nice downhill walk cause hadn't been raining for a week, but after rain I would't recommend that. You have to cross a small river twice. Then with a guagua back to Samana, the second time I used money. I didn't get any angry looks from the guides. Maybe next time I take one, there were some attractive girls among them ;-)