Change blocks on unloaded chunks

Is there any good method to modify blocks on unloaded chunks? You can do methods like setType(), but nothing will change.

I was thinking about saving block information and change them when chunk will be loaded, but there is no way to check if chunk is loaded (so you can't tell which blocks should be saved and which processed instantly) and AFAIK chunk load events are not working yet, so you can't tell when will chunk be loaded again.