The most effective way to implement this is to have an agreement where every new launch pays a fee based on the orbital debris potential of what they're launching. So that would factor in things like what orbit they are going to, how many objects, what size, what the potential is for explosions, and what their capability is to self de-orbit. The fees collected from new launches should be used to establish bounties for cleaning up the most hazardous objects in the most sensitive places. Let the bounties be collected by whoever gets there first. Let market forces figure out the most efficient method of collecting the bounties.