Seems to strike fairly easily. Received two cuttings 28/1/2021, and put them in a resealable bag. Four weeks later, one cutting had struck and the other had karked it. Small sample size, but the cuttings were taken and posted under heatwave conditions, which is a good test. You can probably bank on at least a 50% strike rate without any great skill being required (this was my first attempt at the bag method).
The struck cutting is currently being hardened up a bit in preparation for being potted out. I may try to beg another couple of cuttings, just to make sure I have a backup bush while they're both tiny.