The cuttings just die. I have tried rooting in water, in soil, with rooting powder and without, woody stalks, soft stalks, with greenhouse and without, they just die in 1-2 weeks.
If you examine the stems of the scented geraniums you will probably find they are covered in fine hairs. There is a tendency to overwater geranium cuttings of all kinds, and the hairs just make the problem worse. A useful technique when dealing with geraniums of all kinds is to take the cuttings, then put them flat on a table and cover with newspaper and leave them for 12 hours or so. In this time they will dry down and produce a callus at the cut end. Joy for you if you see a nice thick callus form. The hairiness of the leaves will stop them from drying out too much. They may look floppy but they will perk up when in soil. Then pot up into a potting mix and keep the cuttings on the dry side - force them to go looking for moisture, but not bone dry.