The whitish “oxidation” you occasionally see on your Hunter boots is actually a process known as “blooming.” It is when wax injected into the rubber compound during the vulcanization process appears on the surface under certain conditions. The wax appears on the boot as white marks or a whitish patch. This is completely normal for Hunter boots, and the blooming can easily be removed.
Wet a soft cloth with warm water. Wring the cloth thoroughly to remove excess water.
Wipe the blooming off with the damp cloth. Avoid soaking the boots while wiping with the cloth.
Set the boots to dry in a cool, dark location, and allow them to dry naturally.