Plant Foods Hum Nutr 1992 Oct;42(4):285-90 The chemical composition and nutritional potential of the tribal pulse, Abrus precatorius L. Rajaram N, Janardhanan K Department of Botany, Bharathiar University, Tamil Nadu, India. The boiled seeds of Abrus precatorius L. are eaten by the residents of the Andaman Islands in India. The seeds were analysed for proximate composition, total (true) protein, seed protein fractions, amino acid profile of seed proteins, minerals and certain antinutritional factors. The seed proteins are rich in most of the essential amino acids, and they are deficient only in cystine and threonine, when compared to the WHO/FAO requirement pattern. The antinutritional factors (total free phenols, tannins, trypsin inhibitor activity and haemagglutinating activity) were also investigated.
Perhaps the natives have a method of detoxifying them. I assure you that untreated seeds are deadly. People have been poisoned by merely pricking their finger while trying to drill holes in the seeds as jewlery. The toxin, Abrin, is a protein, however, and there has been some speculation based on experiments with rabbits that one could build up a resistance to it. Perhaps these people (the Andaman Islanders) prove that.
You'll notice that most of the preparations involve the roots, and the ones involving the crushed seeds are for things like worm infestations and cancers, where the "Everything is poison, nothing is poison" perspective comes into play.
As a side note, here in the South, Abris is employed by children as a "pea shooter" projectile. In India, it makes a more sinister weapon.