As promised. I went out today and cleaned up the drivers rain gutter. All I used was a couple flat screwdrivers to scrape it out, a drill with a wire wheel to clean up after and a die grinder with 240 grit discs to prep it and final cleanup that the wire wheel missed. Took about an hour and a half to get the drivers side this clean, maybe less.
First picture is untouched seam sealer, second and third are the surface rust found underneath, and remainder are cleaned up and tools used
Thing to remember is that even though the sealer looks fine it can be a mess underneath. As you can see from one of my pictures there was only a small crack in the sealer, but the surface rust underneath shows. Also this is a Nevada car. I have seen holes created under the rain gutter seam sealer in rust belt cars.
also ran the steering column bolts in my ultrasonic cleaner to get the loose crud off them before I put the hardware in the evaporust. That way my evaporust lasts longer. Came out pretty clean for only soap and water running it at 60 degrees