electric fencing isn't as bad as alot of people think, in my opinion. It's only a small shock. But I think it's pretty pointless after the dog figures out that once it crosses a certain boundary, that it's fine lol. That's what happened with my aunts golden retriever, Brandy. She figured it out right away
But if your friend isn'tgoing to leave her dog unsupervised, why would she need this anyway? Couldn't she just call the dog when she sees it wandering?

I'm not sure about your other question? I would probably try using wood, although I'm not really sure...that would get rotten faster...I would try planting grass, but that's no good when winter comes along and ruins it lol I guess you'll have to leave it to some one else for that question lol, I'm not help