Chullin 36: Can Blood be Like Water?

We have learned that when something or someone who is tamei, ritually impure, contacts food that has been made wet, that food becomes defiled.  That state of being wet might be understood as necessary to prepare the food for defilement, and that would be done by one of the seven liquids.

A baraita teaches that not all blood can serve this purpose of 'preparer'.  In Bamidbar (23:24) the Jews are compared to a lion that drinks its victims' blood.  It is concluded that blood from a dead creature will serve this purpose. If the blood comes from an animal still alive, then it is flowing blood.

Rashi teaches that blood that flows from an animal at the moment of death is the blood that is permitted.  Tosafot argues that the blood would still be considered to be blood from a  living animal and that it is only blood that comes from an animal at a later point that would be considered to be dam challis.  Rashi and Tosafot agree that blood collected from an animal while it is still alive (from an injury or bloodletting) does not prepare food for potential ritual defilement.

Should any blood from ritual slaughter be considered like water for this law?  There are laws that teaches us that blood might be poured unto the earth as water (Devarim (12:16).  This is rejected by the Gemara - that proof should be used for other purposes.