In most houses, you can just lean over the foul line and examine the reflection of the fluorescent lights on the lane. Just see if the reflection gets dull outside a certain board and that'll give you an idea of where the hook is. (No oil, less reflection.)
This will tell you where the oil stops as the lanes are usually blocked. At least it's that blatant in Canberra and Sydney! It used to be called cheating once upon a time.
Cheers,
Jason