Wash. Rev. Code § 6.27.320
In any case where garnishee has answered that it is holding funds or property belonging to defendant and plaintiff shall obtain satisfaction of the judgment and payment of recoverable garnishment costs and attorney fees from a source other than the garnishment, upon written demand of the defendant or the garnishee, it shall be the duty of plaintiff to obtain an order dismissing the garnishment and to serve it upon the garnishee within twenty days after the demand or the satisfaction of judgment and payment of costs and fees, whichever shall be later. The attorney of record for the plaintiff may, as an alternative to obtaining a court order dismissing the garnishment, deliver to the garnishee and file with the court an authorization to dismiss the garnishment in whole or part, signed by the attorney, in substantially the form indicated in RCW 6.27.160(3). In the event of the failure of plaintiff to obtain and serve such an order or release, if garnishee continues to hold such funds or property, defendant shall be entitled to move for dismissal of the garnishment and shall further be entitled to a judgment against plaintiff of one hundred dollars plus defendant's costs and damages. Dismissal may be on ex parte motion of the plaintiff.
RCW 6.27.320