I have Spicher's vinyl floor cloths all over the floor of the store. They experience very high foot traffic and can get soiled over time. (The store is in New England so all the salt, dirt, and sand during Winter is brought into the store.) Even with routine vacuuming and mopping (Swifer Wetjet), dirt can still build up since the vinyl is textured. Normal everyday use in homes most likely won't need the be deep cleaned. However, some customers ask for my suggestion on how to deep clean. Previously, I posted a procedure to deep clean the cloths, but have discovered a new procedure that I prefer. 

I used a Steam Shot handheld steamer along with a bucket of water, soft, absorbent sponge and a very soft bristle brush. 1. Spray the hot steam on the vinyl. 2. Using the brush, lightly rub the surface. 3. Use the sponge to absorb the water and wipe away the dirt. (See it in the picture.). 3. Dry the surface. 

I find this method less harsh on the vinyl than my other method using detergents. (Which is not recommended by the manufacturer.)