What SE needs to do is focus on the root of the problem--the incentive. The issue isn't the fact a pet can auto attack, the issue is how easy it is to kill chigoes for geodes. 5 minute repop, can easily kill with a crit hit/JA/WS and still get the drops, even though no xp earned--and geodes are suspected to drop on a 5 minute timer.

They need to change the dynamics for getting drops. Several have posted in here the idea that if the PLAYER doesn't actively engage somehow, no xp/item rewards (ie, passive auto pet kill, no drops). Another way could be to extend the already existing code that negates xp on crit-hit/JA/WS instant kill to negate any drops as well. The later is probably a much easy change to make, as the framework for negating xp already exists.

Make it less profitable to farm them in the first place, and it will free them up in general as a farming target.