Digging around the internets, it seems he prefers to use his pegs instead of a memory palace, and goes into detail in the book “How to develop a super power memory.”
Looking at the transcript of that podcast, he doesn’t directly address it but I think the whole story about remembering Pennsylvania was meant to show you something he does instead.
Think I can see where he’s coming from, when you just look at it as ‘encode what you want to remember, then attach it to something’, the memory palace can seem unnecessary, and in my limited experience often is.
I don’t agree with him on it being outdated though, or necessarily just for lists (assuming he means lists like grocery items). I encoded some details about the element argon in a memory palace over 4 loci, and with just a small handful of reviews (mostly when someone here mentions the table of elements I get curious and see if it’s still there) I only have to mentally “glance” towards the MP to tell you that Argon’s a noble gas with the symbol Ar and atomic number 18. It’s the third most plentiful element in the air, and has a mass of 39.948.
Far too easy and effective to be out of date, but that doesn’t mean you have to stick with it, if it’s not to your taste.
Found a post touching on it in these forums.