The Creator didn’t arrange reality such that there are substances that can induce spiritual advancement. It’s only through one’s inner work, through our reality. If a substance is for detaching me from the regularity of our reality, it’s also certain that it detaches me from the ability to work spiritually since the Creator made the reality ideal for this work as it is.
Those called Israel came from Nations of the World originally. Some of them came during Abraham’s time, some during the time of Moses, some later. Anyone can be part of them, depending on if they’re given this kind of desire that is directed at the Creator.
The Nations of the World are necessary parts of the soul to which we all belong. Each part has a part that relative to it belongs to the Rosh (head); these parts together are called Israel. They’re from the Nations of the World, but they’re the parts that can belong to the Rosh.