Removing "all traces" might be difficult: mining endeavours delve into layers hundreds of millions of years old, so you'd need to wait at least that long for new crust to be formed and intact mineral deposits to reappear. Even so, very old cratons would survive and their isotopic ratio and composition might give the game away.
Unless you had the technological level and power to reform the planetary crust, essentially 3D-printing a pristine surface every time complete with artificial isotopes. That could be achieved comparatively quickly: the land surface is about 150 million square kilometers, and if you had machines capable of restoring one square kilometer per year, 150,000 of them could do the deed in a paltry one thousand years.
Keep the seed population numerically stable in separated enclaves, understimulated and half-doped, barely able to care for the children, and within three short generations culture will have disappeared, and maybe language too. You just need to supply them with water and food so they don't starve and don't need to reinvent agriculture.
When the planet is ready simply open the enclave and force the people out of the Garden of Eden, to work for their food.
It all boils down to what kind of traces the previous occupancy left. This in turn depends on its technological level. Bronze Age civilizations managed to dig sizeable copper mines, whose remains are still to be found today. More to the point, the copper isn't - it's locked in wires, pipes, rain-gutters and so on. Destroying said pipes and rain-gutters would simply enrich the environment with minute quantities of copper oxide particles, not reform the original copper ore.
So, the next occupancy might or might not find the holes where copper mines were, but it's a given that they won't find much primeval copper ore to process. The same goes for almost all other metals, except maybe for iron (there are biologic processes that concentrate iron ions into harvestable bog iron).
You can harvest the population, and re-seed it - then what happens? The next occupancy will not be able to reestablish a technological base with the same ease, since any easily reachable mineral deposits will already have been depleted. This, of course, will not prevent their being fruitful and multiply, and establish a primitive civilization in the following thousands of years, when the harvesting cycle can start again.
What it's unlikely you'll be getting is a technological, let alone advanced civilization anywhere beyond the first cycle.