About a quarter of the time, yes. The curative effect was from the fever rather than directly from the malaria parasite, and they were experimenting with machines to heat people up relatively safely and reliably without needing to infect them with malaria when the discovery of antibiotics made the whole approach obsolete.

Link. Paul de Kruif’s book “Microbe Hunters” is a fascinating view into the state of microbiology a hundred years ago, when the idea that scientists could create a treatment that would cure a disease was still somewhat audacious.