The power washer seemed like a good idea. House has vinyl siding and missus has been after me to clean off the green mold on the south side for at least a year. Will buy one of those long wands at Walmart in the RV section and some cleaning detergent stuff made for the purpose.
Not sure I will take up the old caulk (if that is what it is) at this point or not. Dicor seems to be the goop of choice. When you say caulk, I assume you refer to the black stuff? There is a caulk type stuff at the union between the side panels and roof. The black stuff is only on the penetrations.