Mealy bugs - will this work?

I recently bought a syngonium albo and noticed a few mealies in some of the leaves on the way home. I’ve dealt with plenty of pests before but have had the pleasure of never encountering mealy bugs until now. this is my plan to destroy them (hopefully). please tell me if this sounds promising, and if there is anything else I should/shouldn’t do to make sure these devils die and don’t spread to my other plants. The plant is already quarantined.

1. I have already used Bonide granuals (imidaclorpid) in the soil and gave it a good watering. I’ve had good success using this for thrips but I know mealies are a different story.

2. After a couple days to make sure the imidacloprid really gets into the foliage, I’m going to chop it up and save only the newer and healthier looking foliage. hopefully between 3-6 cuttings. I’ll spot kill any others I see.

3. Drown the cuttings in water for a day to hopefully suffocate any stragglers

4. Propagate and start the plant over.

does this sound effective? i’m only seeing horror stories and I want to nip this in the bud as quickly as possible. should I follow up with anything after all of this? any additional tips for eradicating these dudes?