Good luck. Americans won't even differentiate Washington State and Washington D.C. Even the AP guidelines say that "Washington" is ubiquitous shorthand for "Washington D.C." and recommends against shortening it to "D.C."
Americans do! If you are west of the Rockies, Washington resolves to the west. If you are east, it’s DC, and you have to say “you know, where Nirvana is from.”
Don’t get me started on east coast dumdums pronouncing Oregon as “Orry-gone.”
The most hilarious thing is that I learned recently that when they applied to be a state, the people from WA requested to be the state of Columbia. But a Kentucky rep said that would be too easily confused with the District of Columbia, and Congress changed it to Washington.