So, this is Arena exploit. Warrior only.
Want more skill? Have mace skill 281? or something.
Go to the Arena, and in the beginning you have 1 minute to cast free spells / Abilities. Use Whirlwind, and you will gain skill!!!
As Whirlwind has 10 sec CD, you can use it 6 times.
I have tested this
will post screenshot as soon as possible.