I recently did this after I acquired my Pagoda earlier this year. Take your time and do one small area at a time.
A pressure washer is a lot of pressure that can damage parts. What I did was use engine degreaser and a pressurized water sprayer by Griots
https://www.griotsgarage.com/product/pump+up+sprayer.doI found it very effective to spray on the degreaser, scrub with bits of 3M scrubbing pads, rags, etc. and then rinse with the sprayer. Way less water is used and not spilled all over the floor and you can control the spray much better.
To really scrub the tight spots I wrapped cloth around the end of wooden paint stirrers and chopsticks.
Here’s the sprayer looks like, and the before and after photos