The majority of the time my ASFs are dead within 15 seconds of being constricted. I definitely would agree from my own experience that constriction is more humane most of the time then gassing. However, it most certainly can drag out to over a minute or two if the prey is either too small or too large. Too large of prey can also pose a risk to the BP as it takes a while for the animal to die it can fight more in the BPs coils. My ASFs rarely even kick when they get coiled.