you're right wolfpox that it definitely isn't science. Rather it's Oda's standard brand of science fiction.
Oda tends to use science as a theme for non-devil fruit related super powers rather than magical abilities. Instead of magic wands or kamehameha beams he just uses a popular scientific concept as a basis for a superpower. For example, django's hypnosis ability, cp9's rokushiki techniques, the climatact, and franky's carbonation powered engines all are based on valid scientific theories that are tweaked slightly to be more entertaining and pwoerful.
The zombie resurrection concept is likely taken from Mary Shelley's Frankenstein, which was based off of a real world debate. In the early 1800's researchers would go around electrocuting dead animals to watch their limbs twitch and some researchers thought that it would only be a matter of time before one could use this electricity induced animation to fully reanimate the dead.
It's not too much of a stretch to combine those old theories with modern equipment like the defibrillator and some made up special embalming fluid to explain the resurrection of dead matter in a science fiction manner. You can even see the equipment to monitor the electric current strength at the back of Hogback's lab.
So, there's no need to invoke magic in this situation because science fiction more than fills the gap.