Wash. Rev. Code § 84.56.240
If the county treasurer is unable, for the want of goods or chattels whereupon to levy, to collect by distress or otherwise, the taxes, or any part thereof, which may have been assessed upon the personal property of any person or corporation, or an executor or administrator, guardian, receiver, accounting officer, agent or factor, the treasurer shall file with the county legislative authority, on the first day of February following, a list of such taxes, with an affidavit of the treasurer or of the deputy treasurer entrusted with the collection of the taxes, stating that the treasurer had made diligent search and inquiry for goods and chattels wherewith to make such taxes, and was unable to make or collect the same. The county legislative authority shall cancel such taxes as the county legislative authority is satisfied cannot be collected.
RCW 84.56.240