Why can't I climb the statue

Hint 1 of 5:

Did you listen to Chris and Erik from your room last night ?

Hint 2 of 5:

EXAMINE STATUE.

Hint 3 of 5:

They oiled the statue.

Hint 4 of 5:

You must cast a spell to remove the oil.

Hint 5 of 5:

You need to CAST WOOSH ON STATUE, if you have the spell.  +10 points