Hello again,
So this is a pretty heavy duty anti-slip flooring you're cleaning. It looks like the wheels from the chairs are leaving those stains?
Here are a few things you can try:
Tennis Ball:For this you'll need a tennis ball and a wooden dowel or something similar. Make a hole in the tennis ball a little smaller than the dowel (at least half way through the tennis ball), then glue the dowel in the hole and let dry.
You don't necessarily need the dowel but it will help not having to bend your back as much. Rub the tennis ball over the streaked area. You don't need to use a cleaner, just start rubbing the tennis ball across the floor.
You might want to try the tennis ball first before adding the dowel, just to make sure it works before going to the extra trouble.
Mr. Clean Magic Eraser:The Magic Eraser is a must have in any cleaning arsenal. It works great for black marks on floors, walls, works great on some bathroom surfaces, and much more.
Pink School Eraser:This is an inexpensive cleaning solution: Try erasing the marks using the same type of eraser at the end of a pencil..
One of these suggestions should work for you unless the product you have been using has built up over the top.
I went out to the Altro ContraX website and found their recommended cleaning methods, one for manual and one for mechanical cleaning.
http://www.altro.co.uk/getmedia/ab711f2 ... d.pdf.aspxThis might be of some help to you. If our suggestions don't work, you may want to contact the manufacturer of the floor and see what they suggest.