It is now firmly established that remnant planetary systems orbit and pollute the surfaces of white dwarf stars with heavy elements, providing a unique empirical tool to assess the bulk composition of extrasolar planetary bodies. Yet despite the existence of myriad stars polluted by up to 15 heavy elements, and (self-consistent) model inferences for their mass accretion rates, there remains no detection of accretion luminosity. Only three accreting systems have been observed with pointed X-ray observations, which are expensive as a means to establish robust statistics and enable detections. We propose that eROSITA will serendipitously detect these systems during high-rate accretion states indicated by empirical data and theoretical models. By looking across a large fraction of the sky, eROSITA can provide the first empirical constraints on mass accretion rates onto polluted white dwarfs, provide invaluable information on nature of the (as yet unseen) parent bodies, and directly test theoretical models.