There is always the ability to add your own hormones. Picking up a bottle of rooting hormone will help induce rooting on almost any cutting. I was able to clone lemon basil with this when applied persistently, in a very cool room, on a very small cutting. Basil does not do well in cooler conditions, adding the hormone and keeping the clone water clean offers great help. You can even add a small dose of water soluble nutes, but very small, like one drop, don't burn them.