The ornamental design for a set of cottonswabs, as shown and described.
FIG. 1 is a perspective view of a set of cotton swabs showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof,
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a perspective view of another state of the set of cotton swabs thereof.
The broken lines shown in the drawings depict portions of the set of cotton swabs in which the design is embodied that form no part of the claimed design.