In response to the original poster of this thread, I had the same thing happen with my cast iron when I tried to season it the first time... I did some reading, and it turns out that vegetable oils can polymerize under the seasoning conditions typically suggested!
Best solution I found was just to cook bacon in them on sunday mornings, pour out the excess, rinse off what I could of what remained, and wipe with paper towels. Not an instant solution, but sometimes that old ways are best.
ormandj, cast iron's worth it because once you've really broken a piece in, they become completely nonstick, and very easy to clean. Plus the material holds a LOT of heat, so anytime you need to apply very high heat to food, it's the best material.
No, you don't "wash" cast iron; there's no need to, they just need a quick rinse and wipe, sometimes maybe a quick deglazing.
It's not a "coating" of oil, either. The fat over time completely soaks into the pores in the metal.