Clean with lithofin wexa....
Wexa - 1L
A multi-purpose refurbishment cleaner for the removal of wax films, grease oil, ingrained dirt, floor polish, etc for tiles, natural and artificial stone.
and re-seal with stainstop again.....
MN Stainstop - 1L
A spirit based, Silicon impregnator that penetrates into the surface of stone and forms an invisible film within the pores and capillaries.
Prevents staining from water, dirt and oil, allowing the stone to breathe, and aids maintenance. For use on all polished and unpolished natural and artificial stone.
These products can be bought from CTD.........