Compare two sheets and copy new and delete duplicates in excel
I think you should be having performance issues because you have this:

   'Cycle through all the cells in that column:
   For iRow = 2 To iRowL
   'Call subRemoveNotRequiredR...


So you're going top to bottom and every time you go down and delete a row everything needs to shift up and recalculate and whatever. Go bottom up:

Print iRowL
       'Cycle through all the cells in that column:
       For iRow = iRowL to 2 step -1
       'Call subRemoveNotRequiredRows(TempData, SaleSamples)