Consequently have not tinkered with hormone supplements, can you provide the brand name you used.
The specific brand is not that important. Go to any garden center or even one of the 'Box Stores' and ask for rooting hormone.
You may also want to look into air layering. In short, this is a method of inducing new roots on larger stems. You could, for instance, layer off the top and then regenerate the bottom, yielding two fair sized plants from one. Or you could simply cut it back as suggested and then root cuttings, one large one or several smaller ones if the plant is branched. I have never tried to root a large cutting but I have rooted a pencil sized one.