A cigarette dipped in PCP. An organic solvent such as formaldhyde maybe used to extract the PCP, thereby making it available for dipping repeatedly. Smoking embalming fluid, sherming, all refer to the PCP high. The smoking of formaldhyde alone is commonly confused with PCP. Sherm is often associated with gang related activities.
2pac's 'hit em up' "It's like a sherm high"
E-40 mentions dipping his cigarette into "embalming fluid".