Green’s Dictionary of Slang

(drugs) a mixture of phencyclidine and cocaine, thus phrs. talk to Scotty, high off Scotty, see Scotty, to be under the influence of the drug.

1992		T. Williams Crackhouse 21: Others freeze momentarily in order to ‘see Scotty’ — a term for the crack-cocaine high. [Ibid.] 118: Others won’t let a man touch them while they’re talking to Scotty. [Ibid.] 123: Having sex is natural. It’s just better when you’re high off Scotty.
2001		ONDCP Street Terms 2: Beam me up Scottie/Scotty — Crack dipped in PCP.