When I cleaned mine, I used sand paper first, then steel wool. I did not soak mine in vinegar. However, I did use a water/white vinegar solution to wash it with a microfiber cloth. Rinsed, then scrubbed with soap and water. Rinsed, then did the vinegar solution again. Dried it with another cloth. For the seasoning part, I used a clean, dry microfiber cloth to apply an extremely thin layer of oil to the steel and then it went into the oven to do its thing. Perhaps there was too much oil on your steel? TBH, I'm not sure what the residue is that you have. Maybe someone else can chime in here?