The ornamental design for a detergentpouch, as shown and described.
FIG. 1 is a perspective view of a detergent pouch, showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a side view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is an opposite side view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The evenly spaced broken lines illustrate portions of the detergent pouch and form no part of the claimed design. The dot-dash-dot broken lines illustrate the bounds of the detergent pouch and form no part of the claimed design.