Use in full screen mode! Type or paste a word or sentence, press the blue tick mark, type in all the characters that you want to remove from whatever you just typed in or pasted, press the blue button again and wait for the project to do its job.
Spaces count as characters! For some reason this works a lot faster in the offline editor (or at last on my computer it does) I made the background myself. I made this because I thought I accidentally got text into my paper minecraft save codes.