There have been too many times when someone approached me just to say something like "Please, watch your language", or "Use softer language when speaking". I do not think avoiding curse words is the appropriate way to effectively transmit your message. In fact, using curse words owns.
Imagine that someone was really
pissing you off. What do you think it would call him his attention the most? The formal vomit-inducing way of trying to convince him to act the way...