Not sure whether you mean inside or outside, so I'll cover both.
If you have that last drop still in your ear canal (probably not possilble by now), a mix of water, alchohol and vinegar will break the surface tension and allow it to drain, plus it'l modify the Ph and help prevent an outer ear infection (swimmers ear). Personally, I don't add the alchohol, but use the diluted vinegar every few days on long dive trips, to prevent irritation, or infection
If your talking about the fluid inside the middle ear, behind your eardrum, that's the result of failure to clear properly. The symptoms are mild pain, and hearing as if through a resonant tunnel. There may also be increased sound from within your body, such as hearing your own footfalls as you walk, or extra creakiness when you move your neck.
It isn't water but your own body fluid, the same stuff that fills blisters and will drain on it's own over a week or two. As long as it continues to improve you can probably skip the visit to the ENT, but stay on top of it if the pain increases since there's a higher risk of middle ear infection until it drains.
There's little to do to treat this condition, but it can be prevented with better clearing technique.
Lot's of good advice on this forum, I suggest you explore the various threads that discuss clearing problems.