Adult mealybugs can be dealt with a Q-Tip and rubbing alcohol. Unfortunately the eggs are
microscopic and can be blown by the wind or indoors by the grow room fan from plant to plant very easily. Outdoors either ants, whiteflies, even the common fly will nourish on
the tacky egg secretions between the nodes or under the leaves, tracking the substance to other parts of the plant(s). The only solution is a wet one.
Keep spraying...