Once again, those giving the answers are not understanding the true intent of your question, even though you have plainly stated, “If it is remotely possible…”
The common proposal for the use of black holes for space travel refers to the concept that a black hole could be one end of a worm hole which could be a dimensional short cut from one point in our universe to another. This dimensional short cut would be compared to a straw stuck through a balloon. An ant walking on the surface of the balloon could walk all the way around the outside of the balloon to get to the other side OR he could walk through the straw and get to the other side more quickly.
This proposal is applied to black holes because the possibility exists within a black hole. This possibility exists because of the tremendous amount of gravity present within the black hole. And gravity is the curving of space (more accurately, the curving of space-time). This curving of space is not something that we can easily imagine as it involves a curving in a dimension that we cannot see or readily comprehend.
Returning to the example of the ant on the balloon, if the balloon were very large, our ant may not be aware that his flat surface is not really flat. (This is something which we understand; we think commonly that the Earth is flat even though we know it is curved.) All the ant has ever done is walk in a certain direction to get to his aunt’s place which happens to be on the other side of the balloon. When he comes back, he uses the same route. He knows that he takes 12,000,000 steps to get there.
One day, he happens to go through the straw and ends up at his aunt’s place only after 5,000,000 steps. He used a short cut through a dimension that he cannot understand.
This story has been highly simplified and ignores technicalities but the point is that if our universe is curved in the fourth spatial/physical dimension, we can’t see that curve. However, if a black hole is a portal to a fourth-dimensional short cut, then it could be used for space travel.
So, yes it is remotely possible that a black hole can be used for space travel and the science that would support that idea is that gravity does curve space in an incomprehensible way AND a black hole is a manifestation of massive space curvature AND we do not understand yet what the results are of such massive space curvature within a black hole.