I appreciate this answer is three years after you posted your question. I just happened to do a keyword search for "Victorian" and stumbled upon it. First, I'm wondering about your success with washing your building. Second, I noticed no here mentioned the risks of using a non-professional, such as scarring old-growth redwood siding. Please post here what you've done/ Thanks.
When you get ready to repaint the building you may want to consider a new paint that is being produced in Japan that uses sun to break down the dirt on buildings which then gets washed away in the rain. Just a thought. Feel free to contact me at email@example.com should you need additional referrals for washing.
Lots of people power wash buildings either via a cleaning service or as a "handyman." They do windows and the outside of the building. You can make arrangements with them to come out on a regular basis. I would be happy to provide names and telephone numbers if you email me directly.
Happy New Year!