I'm guessing you can do so. If it still isn't quite right, try some regular paint thinner. A few drops is probably all you need. If you are staining where it's warm, a bit of thinner is requisite, for gel stains tend to set up quite rapidly. If you have the can open for long periods, you will have to add drops of thinner to make up for what evaporates.
Casey

I've done this with excellent results. It makes a slicker gel stain.
Diane