In general I tend to say "we don't use those words" or "use your kind words" in a situation like that.

Have you tried telling her what she can say rather than what she can't? Like if she's mad at someone and calls them a stupid poopy butt you could encourage her to label how she's feeling and why ("I'm mad at you because you took my toy" "I'm feeling silly and want to say funny words").

Blame it on the cell phone...