I got a full grid and all of the shaded letters which gave a meaningful surface reading. I failed to get quite a lot of the letters for the message but could see two entries that could be swapped and which had a mutual connection to the title, so I didn’t do a lot of reverse engineering to find the message.
Googling one of the swappers with the key part of the shaded letters led me into the world of commercial laundry. I’m sure that’s not what Check had in mind!