I think that bit is saying the chemists who synthesized the compound were desensitized to it, it’s right after a passage where they were ostracized and sprayed with deodorant at a restaurant during lunch
"The odours defied the expected effects of dilution since workers in the laboratory did not find the odours intolerable ... and genuinely denied responsibility since they were working in closed systems. To convince them otherwise, they were dispersed with other observers around the laboratory, at distances up to a quarter of a mile, and one drop of either acetone gem-dithiol or the mother liquors from crude trithioacetone crystallisations were placed on a watch glass in a fume cupboard. The odour was detected downwind in seconds."
In other words, the smell intensity increases with dilution, _not_ decreases. We must protect this data from the homeopaths.