It looks like the best advice is not to ask him about DXM or anything having to do with recreational use of cough syrop. Because that would scare him away. From what I recall of the DXM faq and other essays of his, he was interested in neuroscience and of course was interested in NMDA receptors and antagonists of course. It didn't look like he had a degree at the time of writing, but he obviously had some knowledge.
Maybe you can use a subtle, innocent approach.Tell him you are interested in neuroscience too and you're fascinated with NMDA receptors because or their role in neurological disorders. Tell him you had even read somewhere that NMDA receptor antagonists have been used experimentally to try to treat depression. And, you are thinking about applying to grad school. Ask him if he has any advice or thoughts on any graduate programs. That should be specific enough to tell you who he really is. Not many people other than DXM WEW could carry on a conversation about those topics.
unfortunately, he's not really looking for conversation. in fact, what he said was "i'm gonna ride your dick like its the last one on earth". i've been sending this guy japanese poetry for months, when i finally got irritated and sent a lurid description of what i had in mind for him (I'm gonna spread your ass like a priest opening up the holy bible, which i think is a good line), he bit. He doesn't want my poetry, he wants my carnal talents. fine, i have those - i know exactly how to gently but thoroughly dominate another man and make him feel safe and *owned* just for a while. but dammit, it would be VERY weird to be will white's studpuppy (and face it, that's what he wants) and not get to talk to him. still, he gets his studpuppy, i get my cuddlebunny, all is good. i think those terms come from Bloom County?
i was a studpuppy in grad school - i'd go visit this guy, fuck the living daylights out of him for several hours, then he'd give me $40 and send me home. said it was gas money. i was a grad student, he lived in a restored antebellum mansion. what the fuck ever, bought me my chronic. he eventually explained that he'd summoned me, via a spell, like an incubus, and he had to pay me as part of the ritual (or i'd drag him screaming to hell, i suppose). man, i wish i had two guys like him right now. yeah, i'm a hoe. i can even run really fast in high heels. <----kind of shit that happens to CCC agents.