Its activated charcoal filter has the primary layer, a secondary layer that filters sulfur gases, and a tertiary layer that filters alkaline gases. Skunk spray

Its activated charcoal filter has the primary layer, a secondary layer that filters sulfur gases, and a tertiary layer that filters alkaline gases. Skunk spray is made primarily of thiols and their acetate derivatives. Thiols (the main ugly smelling ones are both thiols) are organosulfur compounds, and would be filtered by the secondary chemical filter. The gases that make the decaying corpse smell are acidic (AFAIK), so would be filtered by the tertiary layer.