Of course you can use it outdoors! Just bend the plant over, and tie it to a stake in the ground. Or bend branches down and tie them to the main stem at a lower node.
Hey man, you dont need any stakes or screens as you say. Iv seen people use screws and all sorts larf. All you need to do is use thumb tacks, simple. Tack the string to the side of youre pot/ pots. Iv posted some picks from 1 of mine. All lower nodes exposed to more sunlight. Maybe even promoting more lavish growth as well iv noticed. Just remember the longer you leave it, that part will get a lot stronger, and even become unbendable. Good Luck.