There's no reason for a lock.
This is a thread that can be argued over and it doesn't break the rules in any way.
Anyways, for the suggestion itself, I simply cannot get myself to agree to this. First off, sticks don't require pauses between weapons to get the full kb meaning that it can have the full effect by spam clicking. Also, note that with spam clicking being encouraged by the stick, it may cause false triggers to the anti-cheat for an unsuspecting player. Second, kb sticks have infinite durability, meaning that it won't break and can be used for all eternity. At least the punch bow can run out of ammunition to force a camper to get more arrows, or break. Without any restrictions except for sheer range, the kb stick simply ruins the game of egg wars.
Not to mention, it's too underpriced for a kb item. It would be a nightmare trying to fight a team armed with only kb sticks. How will you ever manage to kill their egg?
They can hit you off for all of eternity especially in maps such as space, in which the egg is close to the edge. The cons completely outweigh the pros causing me to go against this idea.