Waffle pans are seasoned through usage. If you clean the pans too well, they won't work right. It's a bit like cooking with a cast iron skillet. If you wash it with soap and water, you strip the oils off of it, and it will rust.
Use some Pam or similar product when you get ready to make your waffles. Spray the lower pan, add your batter, and then spray the upper pan. Close the waffle maker up quickly after spraying the upper pan.
To clean off old material, it's easiest to scrape it off with a nylon scraper, taking care not to score the metal. A bit of the cooking spray will help on the most stubborn baked on material.
I personally prefer to use the batter that requires the addition of cooking oil, and I still spray the pans as well. This leaves me with a seasoned waffle making machine.
When you've finished with the waffle machine, wipe down the outer surfaces with warm soapy water, followed by clean water. Clean the pans the least you can. Usually, if the waffles are leaving little to no residue, we just wipe the pans clean with a paper towel, and then put it away.
By the way, the first waffle in any given batch seems to never be as good as the ones that follow. We call this one the "sacrificial waffle" and move on. Our dogs appreciate it!
Best regards. Hope that you found this somewhat helpful. --W/D--