Don't use regular veg oil on it - use coconut oil or lard or something that won't gum up on you. You can get spray coconut oil now which makes it really easy.
A good way to clean stuff that wants to stick - once you've removed your yummy meal and the pan has cooled off, sprinkle it liberally with kosher salt. Let sit at least overnight - 24 hours is even better. Then use one of those plastic scrubbies and scrub that salt all around the pan (dry) - shake excess out into garbage, then fill pan with good hot water, use the same plastic scrubby to remove any stubborn bits, rinse well, dry with paper towels. Put pan on burner and turn it on til all moisture is evaporated. Turn off burner, spray with coconut oil (or a dollop of the stuff from a jar) and carefully wipe with a paper towel to coat the entire inside of the pan with a thin film. Let cool completely, put a fresh paper towel in the pan and store in a dry place. Mine stay in the drawer that's built in beneath the oven.
I've had people give me cast iron pans that were so gummy from bad oils and bad care that they gave up. I put them upside down in my self-cleaning oven and run the clean cycle. Let cool completely, wipe out any remaining ash or residue, then coat liberally with good oil (right side up) and plunk back into the oven - set it at 350*, when it's up to temp, turn off and just leave the pan in there overnight.
I do occasionally use a very small amount of dishwashing soap in mine if I've seared lamb or something in it. As long as you swish it around, rinse thoroughly, then do as suggested above, the soap won't hurt a properly-seasoned pan.
My favorite is a 12" skillet that my DH's Dad gave to DH's Mom when they got married. DH is now 63 years old so you can figure how old that pan is! It is very nearly nonstick. I still don't do eggs in it though - never have had good luck with that. But you cannot beat it for searing meat or a myriad of other cooking adventures.
My fave - panseared marinated lamb (I get these great ones at Costco that have a nice fat cap) which I then finish in the oven. That pan is great going from stovetop into a screaming hot oven to finish meat!
I think Lodge's website recommends using food grade flaxseed oil to season.
