White Grout Refresher Pen - Refresh Old Discoloured Grout in Bathroom & Kitchen

I didn't find this made any difference, when I could get liquid out it was mostly colourless, and yes I did shake it lots. I have had to go over it with a different make, although it has provided a good base for that in places.

AN ABSOLUT WASTE OF MONEY.I BOUGHT A NUMBER OF THESE PENS AND NOT 1 OF THEM WORKED I THREW THE WHOLE LOT IN THE BIN.

works well

Absolutely useless - bone dry