After recently having paid more attention to the Religion Forum lately than I used to, I've been reviewing certain passages (mainly in the New Testament letters) about speech and related conduct. They're interesting, especially when read in contrast to what sometimes happens in the Religion Forum. Consider, for example, Philippians 4:5, and how often those who identify as Christians practice it.
Whether or not the rosary helps defeat sarcasm--and I'm not going to pass judgment on that question right now--sarcasm seems less important "biblically" than the world tries to make it sound. Although I don't see a total biblical prohibition of sarcasm, whether by command or by example, and one can arguably point to examples of the use of sarcasm by "good people" in the Bible, neither point seems to commend sarcasm as a leading virtue in Christian speech.
Unless I'm missing something big, I'm not aware of any command to cultivate one's sarcasm skills, even on behalf of apologetics or for some other presumably pressing reason. Unless I'm missing something big, certainly the Bible doesn't seem to commend sarcasm as one's dominant mode of speech or posting. I'm not even sure that sarcasm helps much against Boko Haram.