I prefer to use drying oils on my spoons. I'm a little grossed out at the thought of constantly eating rancid olive oil as it wares off. However, it seems totally plausible to me that if you are using a spoon/ bowl/ whatever often enough, the oil never sticks around long enough to get really rancid. So the main advantage of walnut or flax oil is that you never have to re-oil. The main disadvantage is that it takes a long time to cure. I wash my spoons in hot soapy water, though it's always by hand, never in the dishwasher. And I try not to leave them soaking in dish water overnight.
This is how I finish my spoons: warm the oil on the stove. I use a tall, narrow, "asparagus" pot in a larger pot filled with water to keep the oil from getting dangerously hot. Dunk the spoons in the oil for a few minutes. When you take them out, let the oil on the surface soak in if it's going to, then wipe off any excess. Now you wait. If there is excess oil on the surface, it will get sticky, and then eventually harden. Generally, I find it takes about 6 months for the oil to completely cure.
The reason I heat the oil is because it helps the oil penetrate the wood more quickly. You can also just soak in room temp oil for a couple days. But I find when I do that the wood absorbs too much oil, which then slowly weeps out as it is curing. That's not a problem if you are using the spoon while it cures, as you will just wash off the excess oil. But if you choose to wait, you'll have to check in on the spoon every so often to see if it needs to be washed. I also think periodic heating may help accelerate the polymerization process: fresh oil seems to take longer to cure than older stuff, though I haven't taken any notes on this.
I only do the hot soak, long wait process for tableware that's going to get a lot of hard use and regular washing. For fiber tools or something like a fruit bowl, I would just rub a few coat of oil on the surface and start using in a few days.
