  In this work, we use general relativistic magnetohydrodynamics simulations to
explore the effect of spin orientation on the dynamics of gas in the vicinity
of merging black holes. We present a suite of eight simulations of
unequal-mass, spinning black hole binaries embedded in magnetized clouds of
matter. Each binary evolution covers approximately 15 orbits before the
coalescence. The geometry of the accretion flows in the vicinity of the black
holes is significantly altered by the orientation of the individual spins with
respect to the orbital angular momentum, with the primary black hole dominating
the mass accretion rate $\dot{M}$. We observe quasiperiodic modulations of
$\dot{M}$ in most of the configurations, whose amplitude is dependent on the
orientation of the black hole spins. We find the presence of a relation between
the average amplitude of $\dot{M}$ and the spin precession parameter
$\chi_{\mathrm{p}}$ showing that spin misalignment systematically leads to
stronger modulation, whereas configurations with spins aligned to the orbital
angular momentum damp out the quasiperiodicity. This finding suggests a
possible signature imprinted in the accretion luminosity of precessing binaries
approaching merger and has possible consequences on future multimessenger
observations of massive binary black hole systems.
