Ginger
The method I tend to use for erasing memory would not work, here. I prefer to make a gradual change, and any encounters with those involved in the memories being altered will throw the entire thing off, and potentially make the memories more vivid. In theory you could be kept separate from Peter and the others involved for a time, but given the alterations you would not understand why you were being kept away, and likely become confused and frustrated.
I know of other ways, but I am not familiar with them, and it would require study. I can look into it, if you would like.
As for the dreams, I must be present to remove the dream when it occurs. This is impractical, but as an occasional temporary fix, possible.