As WA residents, we're allowed to deduct sales tax.
We don't pay income tax, so the only figure on your Schedule A line 5 should be that for line b, general sales taxes.
If you work in another state (like Oregon) which has an income tax, that number may be greater than your sales tax which you could deduct, but if you work in WA, your sales tax deduction will be greater.
The above should be happening automatically, based upon your zip code and entry in boxes 16-20 of your W-2.
