After watching all of Jodi's interrogations, so much closer in time to the murder, I don't think Juan will scare Jodi at all, and I doubt he expects to do that. He won't let her ramble- that's a given, and maybe that will throw her ever so slightly off her game, but not much, since she'll be expecting his style.
I bet he prepared years ago for how he would cross her if he had the chance, and that if he didn't already know how (and I bet he already knew), he consulted with pysch experts as to how to go toe to toe with a pathological liar on the stand.
IMO, he won't be able to get her to eat her words on anything- she can lie faster than she can think. What he will be able to do is reinforce for the jury that she is a liar, and to throw fact after fact after fact in her face.
As of now, I also think he will not revisit very much of the past 3 days of testimony. He's too smart to get lost in the weeds of refuting each of the mountain of this defendant's fabrications. Seizing on her pattern of snooping into her boyfriends' correspondence and confronting the involved girls would do.
One exception- her very bizarre tale about the drunk lady Jodi found terribly amusing until the lady pressed her cleavage against Travis. Sent into a tailspin of hiding in a bathroom stall for 1/2 hour weeping? Wow.