Thank you. Here are some pictures of the walls and ceiling I am dealing with. We are going to do something to finish those upstairs floors, in addition to filling in the area that was left open to downstairs. And put in a real staircase, there is just a temporary one, and not where I want it. Sounds like the pressure washer is a great option, especially since we already have one. What about all this spray foam around the beams? I think I may just cut boards to fit between the beams and cover that space, after running any wiring in there.
Agree w/ Tom - some sort of chemical cleaning will be necessary to get rid of the smell. Soda (as in baking soda) blasting is also an option, but would be a lot more expensive. It might be necessary, depending on whether or not the chemical cleaning works. Either way, on the interior, it will be a mess. :-) Good thing you don't need to save the floors.
In general, the best process is to wash, preserve (borate-based wood preservatives are always a good idea on the exterior, even in dry climates), stain, and then chink and caulk last.
One course of action w/ the spray foam: cut it/shave it down out as much as possible. Then, tape over top with clear packing tape or duct tape and apply a good elastomeric sealant. We make a couple (Conceal and Log Builder), but we're not the only ones out there so do your research. Do this only after you've applied any interior stains and/or clear coats, and make sure those stains and clear coats are chemically compatible with whatever else you're using.
When you get a minute, read through our booklet called "Keeping the Dream Alive." It's a good basic overview of finishing a log home from beginning to end. It doesn't address all of your specific circumstances, but it will help you know what to look for and how to go about accomplishing the work, whether you do it yourself or hire a contractor.
Hope that helps for now. Good luck on your project!
--- Charis w/ Sashco - www.sashco.com - email@example.com