Hi Becca
Now I understand what you meant
Regular brown Listerine is the first thing I grab whenever I see something I don't like happening. It works very well. On the very rare occasions that it doesn't take care of the problem, I then use Thiomyl. I also use the Thiomyl on my vandas when they start showing those nasty black spots. It won't get rid of those spots but will usually prevent new spots from coming on new leaves.
For the Listerine, don't use the minty stuff (don't know why but that's what I've read
) and I always get the store brand because the brand name stuff is too expensive.