Pocket Clearing can be used for both closed (cavity) and open (core) pockets. By default, Pocket Clearing operates in closed pocket mode. You can enable open pocket mode by either setting the machining boundary to None, or selecting a Stock Contour.
In open pocket mode the machining starts from the outside of the stock whenever possible.
Setting Machining boundary to None
The following images show a comparison of the two modes, as well as an Adaptive Clearing toolpath with similar settings.
The example part with the stock shown in yellow
Traditional closed pocket mode. Machining boundary is set to Bounding box.
Open pocket mode. Machining boundary set to None.
Adaptive Clearing toolpath