Hi Sathwick!
If you have had TMV the previous season, and are bringing new tomatoes (the most vulnerable crop depending upon the cultivar; many are resistant and will say so) into the same space, you want to do scrupulous sanitation: first remove all plant material, plants or debris from plants from the previous crop. You could wipe down inanimate surfaces (not the media, which should be discarded after a TMV outbreak) with 10% bleach solution (bleach diluted 1 part bleach to 9 parts water) - but wear respiratory protection when you do this or at least have all the vents open for your own protection. Then you could also use a nonfat dry milk solution (20% wt:vol) to spray the incoming plants as an extra precaution, upon arrival. If you HAVEN'T seen TMV in the previous season, what you generally do between crops, plus a NFDM spray on the incoming plants, before handling them, would be fine. TMV is always more likely to be in the new plants than to be picked up from the benching, doorknobs, etc, but if workers touch a contaminated area and then handle plants, they could transmit it from a surface to a tomato plant, so extra sanitation is helpful. Washing the whole place down with milk as Elise wonders in her post would be a useful sanitation practice, but it IS sticky, and you may find it leads to sooty mold growth on plants, which is not harmful, but is not attractive. So I think bleach or Virkon disinfection would be better when the greenhouse is empty. The milk is the only option to use directly on the tomato plants, and it doesn't cure infections, just minimizes spread.