Actually, I'm not sure DOR is that relevant to the dopeyness, 3-HO-PCP's affinity to it is pretty weak. Which might be convenient, since Ginkgo's has a strong DOR blocking effect. Of all opioid receptors, MOR is strongest for 3-HO-PCP, which I don't see Ginkgo having any influence on.
I'm not too knowledgeable on what opioid receptor produces what effects (apart from that I know I DON'T WANT KAPPA ACTIVATED FFS PLS NO

). Is it rather the MOR that produces the nodding effect?
Any dope fans with any insight?
Edit: 25g of Ginkgo Biloba extract seems to do a decent job blocking the ototoxicity of a 10mg 3-HO-PCP dose. (Yah.. erring on the side of overkill for this one!)