While this is mostly true, it isn't always true.
Those blue demagnetizers may not be powerful enough to fully demagnetize a watch that is a heavier case and has things like the iron cover over the movement. Those protect the watch from getting magnetized, but also protect it from being demagnetized. But in this case I suspect the watch just needs a regular service, and demagnetizing it should be part of the service if the person you are taking it to is a professional.
When was the watch last serviced?
Click to expand...