The ornamental design for container component for a toilet brush holder, as shown and described.
FIG. 1 is a perspective view of a container component for a toilet brush holder showing my new design;
FIG. 2 is a front elevational view thereof; the opposite side being a mirror image of the shown.
FIG. 3 is a left elevational view thereof; the opposite side being a mirror image of the shown.
FIG. 4 is a top plan view thereof; and,
FIG. 5 is the perspective view embodying the utilization of container component for a toilet brush holder in which the broken line is for illustrative purposes only and forms no part of the claimed design.