Yes, unfortunately time is your friend with seasoning cast iron... you need to leave it be whether you use the EZ OFF or lye method, and even electrolysis requires a half day or more. I do not have a self-cleaning oven, but I know most on the WAGS forum don't use that method since some have had pieces crack in two (or know of people who that happened to). There is a suspicion that the more contemporary, machine ground pieces are thicker and can withstand the process better, so I know I would avoid it for anything made over 60 years ago.
I use a stainless steel scrubber to help clean it off completely, then just towel dry as quickly as possible before popping it in the oven to dry 100%. If you are having trouble getting the rest of the gunk off with a wire brush or equivalent, then you need to re-strip it, it's just not done.
The lye method is REALLY easy. Put the piece in, let it sit for days, pull it out, rinse and MAYBE scrub it a little. Everything comes off nicely. And there are stories of collectors forgetting about CI trivets or something in the lye for over a year, the lye won't hurt it a bit.
And yes, the final bit of advise, wiping the piece off until it looks like you removed all the oil/PAM/Crisco is KEY. I have had to start again when I got a splotchy design on my pans, thinking I had wiped it down well. Terrycloth towel (I picked up a pack of 18 in the Walmart auto department for $4 or something) will do the job because it really soaks up the excess.
Patience is key, and trust me, I know how badly you want to see that gorgeous black surface just staring at you, begging for use. It's worth doing it right