Looks good…Nice work. From looking at the first pic I agree… you did not need to sand the swim step though.
If it’s closer to go to Home Depot or Lowe’s than it is to get to West Marine for teak cleaner… you can also use TSP cleaner on your swim step. They have it in the paint department. Depending on your “honey do list…” you can also use it to clean and prep a wall if you are removing wall paper or just re-paining an old wall. I have used both “teak cleaner” and TSP… both worked fine.
I like the solid swim steps. If you have spaces like I do on mine you can use brass wool to clean the areas the scrub brush can’t reach.
I usually do 2-3 coats of oil. The oil seems to soak in way better on hot days. That means I only have a few days out of the year I can do it her is Seattle.