Hi there,
I'm still a student but I think this is what you need.

for ( iterate through 1st array dimension)

{

for ( iterate through 2nd array dimension)

{

for (iterate through 3rd array dimension)

{

delete array [1st] [2nd] [3rd]

}

}

}

Let's say all array's go from 0 to MAX.
then the first element to be deleted is
array[0][0][0]
second one
array[0][0][1]
3rd
array[0][0][2]
lets say the 3rd dimension reaches MAX value, the 2nd dimension will then be incremented(by 1) and repeating the 3rd dimesion loop.
so:
array[0][1][0] untill array[0][1][MAX]
then:
array[0][2][0] untill array[0][2][MAX]
when the 2nd dimension reaches it MAX( array[0][MAX][MAX])
we can include the 1st dimension in the acces loops, because the array[0][..][..] has now been completely deleted we goto:
array[1][...][...] basically the above will be repeated untill the 2nd and 3rd dimension reach their MAX value and the 1st dimension is incremented again to:
array[2][...][...] untill array[MAX][..][...] has been reached and all elements have been iterated through.
If you don't understand this, try drawing the situation, I suggest drawing it 2D because it's easy and the logic behind this is analog to n dimensions.
you iterate through the x and then through the y
delete all X within the y== 0 range
then increment y +=1, delete all X within the new y == 1 range
etc etc etc...