As with any advice from the Watchtower society, they expect you to take it seriously and when everything falls apart and you find yourself in jail for perjury, you're on your own, sucker! Any one who hasn't learned that lesson the hard way already, or at least had seen it played out in other ways, will eventually figure it out the hard way.
Just think about all the crap advice they have given out on so many things that have serious consequences (financial, health, safety, jail), like advising against blood transfusions, advising against college, advising against registering to vote or being drafted, advising an abused wife against leaving her spouse, advising against bringing in the police for sex crimes. Now they are advising people to commit perjury in court. I thought "jehovah" hated a false witness, but not the Watchtower. These monsters really don't care about anybody but themselves.
Would they even enforce this "counsel"? What are they going to do if you do tell the whole truth in court--disfellowship you? I guess that would be a fitting testimony to the Watchtower's general lack of ethics.