The thing is I get were you are coming from. SSA is failrp and I know from personal experience that screenshotting SSA is hard to do and it gives people who are not recording a disadvantage, but killing people for SSA is using an in game RP situation to solve a OOC problem. Which is no different then rdming someone for dis in OOC which we all know isn't the right thing to do.
A counter suggestion would be add one of 3 suggestions:
1. Make the stun stick do 1 hp so that staff can see when it does damage and putting it under the ARDM/RDM category while making it not do so much damage that it will kill a lot of people.
2. Make to so that the stun stick will appear in logs.
3. remove the stun stick all together considering I haven't seen it used practically except in a few rare occasions