I think few would find the word "buried" rude. It certainly isn't technical -- it's a very common word. If you are talking about disposing of dead bodies in general, "buried" is probably the most common word for this idea.
As others have noted, "laid to rest" is sometimes used as a euphemism. It is pretty much only used when speaking to the family or close friends of someone who has just died.
"Interred" is the technical term. You almost never hear someone say this other than funeral directors and cases where someone wants to sound very formal and respectful.
I don't have a survey on this, but I think most people would say, "My mother is buried in Pennsylvania" and the like without a second though.