For real, I think you could use it to change your memories of the past but I don’t think one would be actually able to change the past, not like that at least.
Think about it: “the consequences could be catastrophic” if anyone could change the past. And if the past has been changed how could you notice the change outside it?
One cannot prove it, though we could have a precise experience of it: consider that you want to change the past. While there you have some false memories that make you believe that something ‘A’ actually happened but it hasn’t happened in reality/your timeline. Then after you wake up you could believe that you managed to avoid the happening of ‘A’ changing it into ‘B’. But since it happened before did time travel, perhaps ‘B’ was always the “actual reality”.
Bottom line: I think you should try it mostly for fun. Maybe you can use it to recall some nice event you have forgotten. Do not be obsessed about changing things.
In case anyone succeeds time travelling, remember to post here. 
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Is this poetry?[/spoiler]
Anyway, if I sleep long enough, it’s like I have time travelled to the future. (Yes this sentence is a joke.)