Get the mineral spirits (preferrably low odor) and some lint free rags like bed sheets. Start with lots of solvent on the rags and go to town on the dark areas. The sooner the better before thie finish cures completely. Scrub like you are cleaning the oven. Get that extra finish off the surface. If it has penetrated completely into the wood, you probably need to do another coat of stain on the entire project, just apply it more sparingly and wipe it off the surface promptly. The dwelling time for products is highly dependent on temperature. Warm temps cause it to dry on the surface quickly so care must be taken when applying.

I used to stain and lacquer furniture at a shop in Tucson, AZ. During the summer I would stain in the morning when temps are cool and spray lacquer in the afternoon. We would add thinner to the products to help increase the work time. After staining, I would wipe with a solvent dampened rag rather than a dry rag if the surface became sticky or blotchy.

Once the binder (varnish, usually) has cured, it is insoluble in mineral spirits. Well, technically, it was never soluble in mineral spirits, it was only thinned with it.

Adding a tablespoon of mineral spirits to the gel stain before using will increase the working time.

The other thing was to leave the back off until the staining and finishing is complete. That way, you have no three-sided concave corners, and you can see better.

Now, I would probably try some Scotch-brite pads lubricated with mineral spirits and try to buff off the excess. The fall-back scenario is to get a can of paint stripper and hit the reset button.

The problem may have been your prep. Gel stain should not be applied directly to raw wood as a general rule. A conditioner or filler would have helped give you an even finish. Porous woods like Oak , be it red or white, benefit from a filler to even the surface prior to staining.

While this may work for you, this sure is not my experience nor in anything I've ever read.

Blotching is generally not a problem with oak. Gel stains, by their design are thick enough so that they don't penetrate much, making a conditioner superfluous.

Fillers are more of a style issue than requirement. If you want a glass smooth finish (generally more formal pieces), you fill. If you want to see the texture of the wood and its grain, you don't.

>The problem may have been your prep. Gel stain should not be applied directly to raw wood as a general rule. A conditioner or filler would have helped give you an even finish. Porous woods like Oak , be it red or white, benefit from a filler to even the surface prior to staining

Here is a link that might be useful: Conditioners and Gel Stains

An effective way to seal wood for even gel-stain application is to use the lightest available color of gel stain as a first coat. There is a General Finishes color I use called "new pine" that is very neutral, but seals the wood. The color coats of gel stain will then go on like a toning glaze, all on the surface.
Oak plywood sure can blotch, esp. if it has water spots! (mainly from flop-sweat in my case!)
Casey

I am having a similar problem today. I sanded down my mahogany dining table and then bleached it to get rid of the pink in the wood. I was told by my local paint store that I could apply gel stain directly to it without pre stain but it came out blotchy. I tried to wipe with mineral spirits and some color came off but still uneven. Tomorrow I hope to apply a second coat and hope for a miracle. Any advice is appreciated . This is a bit of work...

I have the same issue with mahoganny table and gel stain! Did your technique help? how did it turn out? Did you apply a top coat of poly or something and did that make it look any better?