There are many elements or variables involved before making this decision. Two of them are related to the process and they are how wet are the boards when they exit the cleaning process, and what type of water was used in the final rinse, DI (Deionized), Distilled, or Tap water?
The other variable is: What is the time cycle between the time the product exits the equipment and the time it will be electrically tested.
If it is tested immediately then the boards must be dry. If the boards are wet coming out of the cleaner, the water can either be blown off with an air hose or allowed to evaporate from the surface of the board.
This is why I asked about the type of water being used in the final rinse as the minerals in the water will be left on the board if the water is allowed to evaporate, hence you need to use DI rinse to make sure there are no extra minerals and contaminants in the water which may impact the dielectric performance of the laminate material.
If the water is blown off then heating them will enhance the evaporation process and provide a dry board quite quickly. Then the boards can be baked for a couple of hours at 100 to 150F to dry the boards prior to going into electrical testing.
I must emphasize however that if the boards are dripping wet when coming out of the aqueous cleaner, it will take a much longer time to evaporate all the water from the surface of the boards and the time in the oven must be determined by the local plant environment, i.e., humidity controls, ventilation in the oven, in-line vs. batch dryers, etc.
If the product is being cleaned in an in-line aqueous cleaners the final blow off must be sufficient to remove all the excess water and the heating system must be sufficient to dry the boards of any excess water.
If they are coming out wet from the in-line system, the capability of the equipment must be questioned and the process should be adjusted to verify the equipment is capable of providing the end results expected, i.e., dry boards.