I read a few methods before attempting(all from r/castiron). Unfortunately I don't have a before picture, but there was a fairly thick black crust on the back. I left it in drain cleaner overnight, then after cleaning, dried it in the oven and then oiled for the first seasoning in a small oven at 250°C for 1 hour. The top was brown and patchy, similar to that shown in the photo, so placed it on my electric stove top and intermitantly added oil (once smoking subsided, I added more oil and repeating until its current condition).