<p>Electrical discharge machining (EDM) of nickel-based superalloys such as Inconel 718 is often limited by poor surface integrity, including thick recast layers, irregular debris, and reduced hardness. This study investigates a sustainable dielectric medium made by dispersing graphene, molybdenum disulfide (MoS₂) and hexagonal boron nitride (h-BN) particles in virgin commercial coconut oil (VCCO). A stirring system assisted by an Arduino is developed to ensure the uniform suspension and stable circulation of the nanoparticles during machining. The impact of these nano-enhanced dielectrics on debris diameter (DD), recast layer thickness (RLT), surface hardness (SH) and microstructural phases were studied. The findings show that graphene-modified VCCO consistently produced the smallest debris sizes and thinnest recast layers due to its superior thermal and electrical conductivity, which enabled efficient heat dissipation and stable energy transfer. The addition of MoS₂ offered intermediate benefits through its tribological properties, reducing particle adhesion and stabilising discharges, while h-BN reinforcement yielded the highest hardness due to its ceramic nature and the formation of nitrides and borides during resolidification. Compared with pure VCCO, the hybrid nanofluids achieved a 2.85-fold reduction in debris size, a fourfold decrease in recast thickness and an improvement in hardness of approximately 1.1 times.</p>