[Closed] Anyone ever actually had success unseizing an avid piston

Just went to sell my Avid brakes, was fitting pads and realised that one of the pistons won't retract fully.

A quick google search reveals lots of threads about how to unseize them, but none appear to end with a positive fix.

So have any of the experts on here actually had success fixing theirs, or are they now only fit for the bin?