Try something along the lines of:
Code:
Sub Demo()
Dim r As Long, c As Long
With Selection
For r = 2 To .Rows.Count Step 2
For c = 1 To .Columns.Count
ActiveCell.Offset(r - 1, c - 1).ClearContents
Next
Next
End With
End Sub
This will clear all selected cells in every second row of whatever you select.