OK, I have the answer to you dust question... but you may not want to know! Most of housedust is comprised of human SKIN. Our bodies are constantly sloughing off dead skin cells. We aren't even aware of it. When you take off your clothes and turn them inside out, the skin particles fly out of it. If you have pets, add pet dander to the mix... YUCK. But that's where dust comes from.
I admire you digging in and deep cleaning like that. Can you come to my house? I love a clean house, but hate to clean. I always think "I have to clean house today", and then gravitate towards the quilting project. I'm terrible about procrastinating.
Hope your day out and road trip goes well... maybe a side stop somewhere fun?