Contamination often from an uncontrolled source provides us with the biggest frustration when it comes to pest control. Meally bugs are but one curse.
I would have a tendency to apply the dunk principle.
Mix in bucket 2 ltr or 1/2 gal of water 2 table spoons of general purpose spray oil, 4 table spoons of mentholated spirit an a tea spoon of washing detergent. Simply Dunk the bulbs in this solution for about 5 mins then pull out do not rinse solution off bulbs then plant up. I would then followup with neem granules on the surface. Followed by normal growing program.