The two most common solutions are:

Reducing the inspection severity (i.e. checking a smaller number of samples by choosing the “reduced” severity);
Skipping some lots randomly.
But then, how to select which orders can receive a “lighter dose” of quality control? In the words of one of the importers who wrote to me:

The ISO 2859-1 standard actually gives a method to switching from normal severity to reduced severity, when a factory get to a certain score.
If you want to follow this rigorous process, you should work hand in hand with a quality control firm — unless you are already familiar with this standard.
Any rigorous method for determining which manufacturers deserve a “skip lot” procedure, though.

As a rule of thumb, if two inspections in a row on reorders of the same product are fine and you trust the factory owner, you can switch to controlling only 50% of their shipments. Make sure the skipped lots are announced at the last moment, and in a randomized manner.