But really this sort of approach to policy is ridiculous. The most absurd would be for proponents of the death penalty to submit to injection/electrocution/gassing...or whatever ...in order to prove that it is 'humane'. This sort of example suggests that being tasered proves nothing at all...other than that attempting to prove the 'humanity' of tasering is pretty pointless; just as attempting to prove the humanity of the death sentence, or corporal punishment or water-boarding by actually submitting to it is futile. It only proves that you (the foolish one who so submits) happily survived it.
There needs to be some more serious thought given to what more objective criteria should be adopted. The emotionalism of a politician undertaking the test, is as futile as the child of the 50s who protests "My father strapped me and ti hasn't done me any harm!"
Until such time as we have more objective criteria, then let us be a bit more circumspect about the promotion of state-sanctioned violence.