John, the word toxic scares the he** outta me!
The entire plant can be sprayed with the alcohol/409mix, let sit for a few minutes and then heavily sprayed with clean water to remove it all including the bugs. The plant should be carefully turned upside down to get the water from the crowns and it's done.
If we watch our chids carefully, most times we can avoid a large mass such as we have here.
Catch the problem before it becomes major...although even those of us who do that do occasionally have problems