Just got my hands on the Cestluck Fin Straightening Tool and Condenser Coil Whisk Brush set. Here's my honest take after using it on my window AC unit and outdoor condenser.

The brush is the real MVP here - stiff enough to clean effectively but gentle on fins. Did two full cleanings and zero bristle loss (unlike some cheap brushes I've used before).

The fin comb... well, it's tricky. The 6-in-1 design sounds great in theory, but aligning it with my unit's fins felt like solving a puzzle. Ended up bending more fins than I straightened initially.

Pro tip: Skip the handle attachment. Way easier to control the comb barehanded when working in tight spaces. Still takes patience - this isn't a quick fix tool.

Noticeable cooling improvement after cleaning though! My bedroom AC blows colder air now, so the effort paid off. For $15, it's decent value if you mainly need the brush.