Less than low energy antitachycardia pacing (LEAP), which is itself a lower-energy alternative to the typical 1-shock defibrillation. Their "1000 times less" means three orders of magnitude. From the abstract of the paper:

We find that, rather counter-intuitively, a single, properly timed, biphasic pulse can be more effective in defibrillating the tissue than low energy antitachycardia pacing (LEAP), which employs a sequence of such pulses, succeeding where the latter approach fails. Furthermore, we show that, with the help of adjoint optimization, it is possible to reduce the energy required for defibrillation even further, making it three orders of magnitude lower than that required by LEAP

Important to note that the study uses:

"an electrophysiological computer model of the heart's electrical circuits "

and

"a simple two-dimensional model of cardiac tissue"

Seeing this phrasing more and more, and I don't like it.

"...using 0.1% as much electricity" feels far more proper.

I assume it means 1/1000th because the phrase makes zero sense.

Why the harsh words and insults? I understand the headline immediately, so as a smart person you probably did too.

Though this phrase has a literal translation to my native language. Maybe the person who wrote this is not a native speaker? But definitely not illiterate, come on.

Than other defibrillation devices, is my default interpretation, because I know they use electricity and there are no other subjects in the sentence.

So: reading comprehension and common knowledge.