I claim the ornamental design for a swivel locking device for a rotary nozzle of a pressure washer wand, as shown and described.
FIG. 1 is a right perspective view of a swivel locking device for a rotary nozzle of pressure washer wand showing my new design, shown in the environmental use;
FIG. 2 is a perspective view thereof;
FIG. 3 is a side view thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a front view thereof;
FIG. 6 is a back view thereof; and,
FIG. 7 is a bottom view thereof.
The broken line showing of the end of a pressure washer wand with attached rotary nozzle in FIG. 1 is for the purpose of illustrating the environmental structure to which the article is applied and forms no part of the claimed design.