Is a ceramic coating worth it on wheels, or does wax do the same job?

They are meaningfully different. A wax on wheel faces typically lasts only about a month because the acidic and alkaline cleaners used on wheels strip wax far faster than they strip more chemically resistant protection. A spray-on rinse-off ceramic sealant lasts roughly one to three months. A properly applied wipe-on ceramic coating lasts the longest of the three and means routine maintenance can be done with nothing stronger than your normal shampoo, because brake dust cannot bond as deeply to the ceramic surface.

How do I prep alloy wheels before applying a ceramic coating?

Full decontamination is required. The ACHQ workflow is: pre-wash with a decon shampoo, then iron remover (such as Bilt Hamber Korrosol) with a 5-minute dwell on faces and barrels, then a tar remover, then a total coating remover (such as Gyeon Total Remover) to strip any old protection. Dry the wheels, then apply panel prep twice on both faces and barrels before coating. Skipping steps here is the most common cause of poor bonding.

How do I maintain a ceramic-coated wheel without stripping the coating?

For weekly maintenance, use the same pH-neutral shampoo you use on the paintwork. Save dedicated acidic, alkaline, or iron-removing wheel cleaners for occasional deep cleans when brake dust has actually built up. Between deeper cleans, spritz a spray-on rinse-off sealant such as Gyeon WetCoat over the wet wheel after washing and blast it off. This refreshes the hydrophobic layer and makes the wheel easier to clean next time.

Do I need to remove the wheels to apply a ceramic coating?

Removing the wheels lets you coat the barrels as well as the faces, which is the more thorough job. However, coating just the faces with the wheels on the car still gives most of the maintenance and self-cleaning benefit. The faces are what you see and where the most visible brake dust collects. A set of four faces can be coated in under 30 minutes once cleaned and panel-prepped. If you coat on the car, coat the barrel first then the face so the coated face is not resting on a surface while you work.