Good question. There have been many theories about what actually takes place in the venom. The current opinion which seems to be supported by German research is this.

Venom is made up of a complex string of proteins which has a slight positive charge, and the tissue in our bodies has a slight negative charge. Seeing unlike charges attract each other, the venom is attracted to the body's tissue. The pulsed DC electric shock alters the ionic charge on the venom and as a result the venom can no longer attach itself to the tissue to distroy it. The body is then able to dispose of the deactivated venom through the normal channels of free radical scavangers etc. in it's own sweet time.

The German researchers were able to deactivate and reactivate the venom during their experiments which disproved previous theories which proposed that the venom was actually being broken down by the charge.

The Vitamin C when injected under the skin near the site of the bite acts as a very potent anti-toxin or anti-oxidant, read"garbage eater". It is one of the things our body normally uses to clean up trash in our system. Giving the body a large dose of it seems to rapidly speed up the process of the disposal of the venom.