On Friday, 23 December 2016 20:40:14 UTC, Enrie Membership wrote:
I've tried many domestic vinyl floor cleaning products but NONE gets the
dirt and grime off to my satisfaction.

The flooring manufacturers sometimes have commercial cleaning solutions that might be more effective.

Steam cleaning with a microfibre mop head may be effective, but don't melt the vinyl or the adhesive underneath.

Owain