I have run into this same problem with the product in the past, and almost every time I have, it's been because of high humidity in the garage. Two things have helped:

1) Sanding with a 320-400 grit paper between the coats. This helps knock down the bumps.

2) Using a fan during the drying process. I use a heavy duty fan, and it seems to speed up the drying time. Once it's aired out a little, I put it in the basement and it's completely dry within a day.

*Something else you could consider is putting one coat of oil-based polyurethane or varnish over the top of it. *Wood Magazine* recommends trying this in their article reviewing the product. 

Here is the review I found: 
[Minwax Antique Oil Finish Review][1]


  [1]: https://www.woodmagazine.com/review/finishes/clear-finishestopcoats/minwax-antique-oil-finish