I say DONT try GoH. Felt like killing myself. Try Anesthetic. I got that same feeling from the Opium Dose though. Next day I was fine... Just kinda messed with me for a day or so.
haven't tried ketamine, but not too surprised about the effects. ketamine is a dissociative anesthetic. in an effective dose it will detach you from reality. sounds pretty similar to your experience although much longer lasting. dissociatives cause hallucinations so your murmurs were auditory hallucinations... it doesn't seem like you particularly enjoyed the dose... so why would you question everyone and do it again? but yeah if you really want to be terrified try GoH.