Dr Keng might not have been able to explain the benefit of frog flesh poultice, but I’ll give it a try. Indigenous peoples have long recognized the powers of skin secretions from reptiles and amphibians, especially frogs. The earliest scientific investigations of frog flesh secretions focused on some of their more exotic uses. So it was in the 1970s when J. W. Daly began analyzing the toxic alkaloid from the poison dart frog that the Emberá Indians use to make their famously lethal blow darts. As scientists began to study other frog species, they found hundreds of skin secretions that had toxic, noxious, anesthetic, and antimicrobial activity. Though all of these substances had evolved to protect the frogs from predation, injuries, or infections, it did not take long for humans to explore their more anthropocentric benefits. Stoners praise the natural high from licking a Bufo frog (something I would definitely NOT recommend!). Macho Peruvians enhance their libido with some freshly blended live Titicaca frog juice. The pharmaceutical industry is most interested in antimicrobial peptides produced by frogs.
Bernhardt M. Treatment of Chronic Ulcers of the Leg With Frog Flesh Poultice. JAMA Dermatol. 2014;150(12):1252. doi:10.1001/jamadermatol.2014.384