I've found the paper:
It describes exactly what settings they used!
"The figure shows the electro-thermal model when the applied PEF protocol was 500 V, 70 μs pulse duration, and 200 pulses delivered at 3 Hz."
In the paper they mention that they need to make changes to the machine. "However translation of the method to humans will require further studies and device development, in which pain reduction is necessary"
At the end of the paper they claim: "Our results suggest that PEF can significantly improve skin function and rejuvenation."