This is my first summer with a feeder (ADF-75) and I figure sooner or later I'll have to clean it.
Anyone have a preferred technique?
Chemicals to use or avoid?

I was thinking compressed air may be helpful.

Just be careful about leaving feed on the ground around the feeder. Ants are drawn to the area, and then you may find unwanted guests the next time you open the feeder. I speak from personal experience, unfortunately...

I had ant issues. Used some grease on the legs and it works.

I clean the solar panels every few months. It can get pretty dusty throwing food daily. I also periodically check the battery connections for corrosion. The TH factory connectors never seem to be a problem.

There's not much hopper maintenance for TH feeders. I just check for wet food, and make sure the hopper's dry before I refill it. I run the feeders to empty every few months just to check things out.