You've already taken a good step by transplanting them and pruning off any heavily infested leaves. If possible (weather permitting), take them outside every week and spray it with the garden hose, this will help dislodge the insects. When inside, the plant can be sprayed with insecticidal soap -- Safer's Soap is a good one -- or horticultural oil, like Neem Oil (but it smells bad!). I find the best treatment is a spray of rubbing alcohol and water, mixed 10 parts water to 1 part alcohol.
Keep watch of the plants, especially at the base of the leaf stems. If you see any white cotton reappear, treat immediately with Safer's Soap or rubbing alcohol on a q-tip.
Don't fertilize the plants while treating for insects, also keep out of direct sun, and be sure isolate them to avoid re-infestation. A little persistence, and your plants will be rid of these destructive little pests!
(Be careful using chemicals, especially in the house, use only products that are marked for inside use -- botanical based products like Neem Oil, rubbing alcohol are safer than chemicals.)
With your care attention, your plants should thrive!
willow