Mealy infestation in large collection (institute sized)

[lazaah]

I recently poped into my local botanical gardens to volunteer my horticultural and botanical skills. Turns out know one has touched their orchid house in two years, it is in a pretty sad state and they have said I am welcome to have at it. Aside from being a cultural jumble, there is a serious mealy infestation that has already taken a few plants. To make matters worse they will be moving to new facilities, and thus, taking this infection to a new site in three months.

To keep consise, how would exparienced growers here tackle an infestation of at least 30 of 150+ pots of all different familes?

My plan is to start weekly alternate neem/oil/soap/pyrethroid-garlic saturations in the evenings (we are coming out of winter now), then re-saturate in the mornings to remove residues. Then what? Start repoting by medium/wetness type?

Pretty much all the plants are labelled to species, and mostly all have cultural conditions documented on the labels, but I am in waaay over my head.

HELP!