If you don t have natural stone tile the easiest way to clean grout is with a solution of 1 part white vinegar and 1 part water.
Cleaning old grout floor.
Wait for the vinegar solution to stop bubbling and then scrub the grout with a scrub brush or toothbrush.
Whatever approach you take once you get the grout looking as good as it can be sure to apply a quality sealer to make it easier to clean in the future.
Steam clean the worst of grout stains.
Particularly on floors with monochrome tiles and white or light gray grout having each tile bordered by an easily dirtied grout line can quickly turn your kitchen or bathroom from clean and crisp to grimy and gross.
The worst part of having tile floors is the grout.
We have a 30 year old teak laminate table.
Put the mixture in a spray bottle and spray the grout in between your floor tiles.