Purchased to go with gift oils and vinegar, so they haven't been used yet!
I had one of these before with a divider that slowed the flow of liquid to a trickle. This made it much easier to distribute your vinegar or oil evenly. These do not have a divider, but they still work well to prevent drips and allow you to "drizzle" your product. The only complaint I have is that they don't fit all of my bottles.
These pour spouts are the only ones I have found that do not make a mess of oil and vinegar. My girls use many different types of vinegar and oil everyday and my counters stay clean! They are great!