Pretty real sure that going into a black hole doesn't mean you can time travel backwards to give your daughter a message through the inside of your house wall.
It's just my theory at this point, but I intend to prove it.
Interstellar story was boring. The effects and some of the scifi were good to great in parts.
I strongly suggest you borrow or buy the book I mentioned. Of course, they go on record and say that what happens in or beyond the singularity of a Black Hole. Christopher Nolan made it know to the Kip Thorton, the author of the book, that he wanted to go as far as what could be educationally theorized. If there was no way to it could be theorized he didn't want it in the movie. I thought the theory was great, but the ideas were kind of far flung at the very end. The Bulk and the Brane of space time are very much popular and accepted theories. I love this kind of stuff.