Hi Anish,
If you are now out of the dry facilites (lucky!) you probably will not have to worry about fumigating at all!
The nature of beverage production and the through wet cleans and sanitizations on a daily basis/per batch, 99% of the time, will eliminate the possiblity of bugs taking hold, laying eggs and completing a life cycle causing an infestation. Wet cleans are fully capable of eliminating the need to fumigate. If the beverage products they make are canned/tetra packed, etc (fully sealed and enclosed) there should be minimal to no risk of infestation of that product, the transport (if kept clean), or the warehouse (again if kept clean).
Think back to your dry experience, I bet they cleaned on the basis of per day or week, sweeping or blow down with conmpressed air only, trying to move dust to break up the life cycle of the bugs/eggs that are impossible to fully remove from dry products. Becuase you could not wet clean, and if the plant was in a hot and humid place like India, you would have to fumigate on a regular interval just to keep infestation at bay!