Sealing or Oiling Ipe Decks:
Ipe is incredibly dense and as such will only absorb a small amount of oil at any one application. As such there is no "one-coat" solution in our opinion. If you were to apply to much oil or sealer at one time it would just pool up and not be absorbed. It is best to build up several distinct coats over time. We apply the thorough "wet on wet" couple of initial coats right after sanding, being careful to not over do it. the deck then needs to "season" a bit (maybe a few weeks or months) then another light coat applied, repeat this light coat approach until deck surface is fully saturated. 3 or 4 light coats in the first year or two is not uncommon depending on your environment. (full sun exposure, especially with lots of reflective glass tends to cook out the oil quicker). Once the wood in completely saturated with oil it is more about touching up.
Application: applying the oil is very easy and can be spayed, (inexpensive pump sprayers work well) rolled, brushed or even ragged on. There is hardly a need to keep a "wet edge" and really the only concern to too much material and/or puddling, which can be handled by back brushing or back rolling. Although, there is little worry about hurting finish by walking on the newly oiled deck, a couple days of drying time is recommended so you do not track in oil on your shoes.
Decision to Oil:
Ipe is one of the rare materials that needs not finish to hold up outdoors, and from a "maintenance free" or "low maintenance" point of view, no oiling are necessary or just maybe a very light preliminary coat . The wood will weather to a beautiful splinter free silver patina rather quickly, as Ipe is so dense, only the surface of the wood weathers with no penetration into the wood (evident when the deck gets wet and looks wood colored again), as such Ipe is easily sanded back to like new as you do not have to sand deep.
Most people when they see Ipe with some oil on it remark how beautifully striking and elegant the wood looks and want to preserve that look. Although not a difficult process it does take several light distinct coats of sealer to get a good finish, and some touching up here and there afterwards, with some locations (total sun all the time, lots of reflective glass) requiring more attention .