[Familyman 90]

Thats a bodge, not a proper job.

The tyre should fit and seal on a clean rim with no need for sealers. This is how they come from the factory. This is how 99.99% of cars on the road have their tyres fitted.

And the sealant won't be a long term cure. If it is the case that the OP is losing air due to alloy corrosion the sealant will only provide a temporary cure, if it works at all, The area will continue to corrode and worsen and will eventually leak again. Cleaning the area with wire will provides a clean surface, but it remains exposed and will continue to corrode. That defers the problem for another day, it does not cure it.

Its little different to corrosion anywhere else on the car. Rub it down, buff it with wire wool...but leave it like that and it won't be very long before you are back where you began.