From my experience:
You can fit about 15 drops of oil in a "0" capsule. You may combine several different oils into one capsule. To avoid risk of irritating the throat, esophagus or stomach, we only use up to 3 drops in a capsule and fill the rest with a carrier, which may make the essential oil more bioavailable. Less many times is just as effective as more and carriers less risk of harm.
Start slowly and see how your system tolerates ingesting the oils. Ask yourself: "Why do I need to take internally?
I typically save oral use for flu or other infections. Taking daily is not recommended especially if you have liver or kidney issues, as those organs have to filter. Otherwise, a few drops with a carrier oil (or on bread) is fine occasionally as needed.
The reason for using vegetarian caps is that they take a lot longer to break down. If I fill them carefully and don't have oil on the outside, I have seen them last for several weeks in a dark jar.