We have modelled dust dynamics in capacitively coupled, self-cleaning reactors with grooved electrodes. Our model includes plasma dynamics, gas drag, complex geometry, and dust motion. Our calculations show that dust is trapped in grooves as observed in experiments. We also have investigated the effect of groove shape on dust trapping and find that circular-cross-section grooves are more effective traps than the square-cross-section grooves considered previously. Finally, we include the results of calculations of particle trapping in the complex geometry of a realistic device.