Wash. Rev. Code § 6.19.050
The sheriff shall immediately return the affidavit of an adverse claimant and the bond and justification, if any, to the office of the clerk of the court that issued the writ, unless the property was seized in another county, then to the clerk of the superior court of the county in which the property was seized or, if the levy was made under a writ of a district court of this state, then to a district court, to be selected by the sheriff, in the county in which the property was seized, and this case shall stand for trial in said court. The adverse claimant shall be the plaintiff, and the sheriff and the levying creditor shall be the defendants. The sheriff or levying creditor or both of them may respond to the affidavit, but no further pleadings are required, and any party may cause the matter to be noted for trial.
RCW 6.19.050