Or for people like me that do not have a repair stand, but has a receiver hitch bike rack on the back of my truck, hang it on the stand. Pull out a 5 gallon bucket, a bit of dish soap, brushes (including one dedicated brush for oily stuff like chains and cassettes) and start cleaning. Might be 10 minutes but I think I spent two hours cleaning my bike after my last tour, it was pretty dirty, I might have spent a half hour on just the chain and cassette.

Hours to build up a new build can be a few or many depending on complexity and if you are building the wheels. I might spend an hour truing up one wheel after I have gotten it laced together. I know that I put more than eight hours (counting wheel building) on each of my touring bikes, but on my last tour I only needed to make one adjustment once and that took less than a minute. On the tour before that I never had to make any adjustments. The point is that if you spend some quality time to do it right the first time, it pays off in the long run when you have a trouble free bike on a tour. So, take your time, the goal is to have a trouble free bike and not to be able to brag how fast you can wrench.