The top recommendations are bonide granules mixed in the soil, rubbing alcohol spray and Botanigard, it's a beneficial bacteria that's applied as a spray. Not all together but as different modes of attack.
For hardcore killing the recommendation is 3 different chemicals;
Thiamethoxam
Dinotefurnan
Immidacloprid (bonide)
Neem drench seemed to be the most effective against root aphids, but that could have been timing too?