cleaning up text documents?

[Thomas Ward]

Hi, everyone. I have some church documents in pdf which I converted from pdf
to text using pdftotext, but the text is vary durty.
There is all sorts of au:, pr:, ti:, etc in the documents.As well as text
art such as -------- and ****** and so on.
Is there any text editors that has the same feature MS Word has for doing a
find and replace on everything, and not find and replace just once and
leave?
For example in Word I would open the document, press control+h, type in a
au:, go to replace all button, and every instance of that text is removed
from the document.
Is there a program in Linux that can do the same thing, or do I need to
write a utility?
Many thanks.