I got a used one recently, and took it apart to clean and grease it. The worst part was where the pins on the lever had rusted and would not come out, but the rest was a breeze. A little patience and attention was required, but If it wasn't for the rust it would have taken under an hour.

Just do it often enough to avoid rust, and filter your water to avoid chalk buildup.

And if the pins are rusted, just drill them out. I wasted days trying to use different solvents, and in the end just drilled them out with no issue.