robgendreau
Explorer
About the only thing you'll need with the stream option is ecofriendly soap such as: https://www.oars.com/blog/5-best-eco-friendly-soaps/
But be sure to remember not to get that soap in the stream. As the URL you cited notes, "That said, it's important to remember that no soap, eco-friendly or not, should be used directly in the river. Biodegradable soaps need soil to be broken down, so follow LNT guidelines and do your bathing at least 200 yards away from any water source."