The ornamental design for a device for delivering a washing agent, as shown and described.
FIG. 1 is a perspective view of a device for delivering a washing agent of the present invention;
FIG. 2 is a front view of the device for delivering a washing agent of FIG. 1;
FIG. 3 is a rear view of the device for delivering a washing agent of FIG. 1;
FIG. 4 is a side view of the device for delivering a washing agent of FIG. 1;
FIG. 5 is the other side view of the device for delivering a washing agent of FIG. 1;
FIG. 6 is a top view of the device for delivering a washing agent of FIG. 1; and,
FIG. 7 is a bottom view of the device for delivering a washing agent of FIG. 1.
The broken lines are included for the purpose of illustrating a portion of the device for delivering a washing agent that forms no part of the claimed design.