Porcelain tiles hold dirt surprisingly well! Many times I get into a porcelain tile cleaning job and the dirt just keeps coming out. I think this is because porcelain tiles are know to be slightly porous.
So what is the best way to deep clean porcelain tiles??
The best thing you can do when cleaning porcelain tiles is get some good high alkaline degreasing chemical. A good tile cleaner that is low foam and specifically designed to remove grease and grime. The advantage of stripping degreasers is that they remove any old tile dealers waxes or products that may have been applied to the tiles in the past.
Another thing you will need is a stiff bristle grout scrubbing detailing hand brush. This will help you agitate your chemical to really remove built up grime in the grout lines.
Harpenden tile and stone restoration 