Thank you I think this is the most graphic explanation. Then a mass suspended close to the event horizont would be in fact traveling very fast related to the sp

Thank you I think this is the most graphic explanation. Then a mass suspended close to the event horizont would be in fact traveling very fast related to the space time inmediately arround and therefore increasing its mass acordingly. Is that right? Could it be possible to use this as a way to extract energy from the blackhole? Or more exacly from the space-time falling into the blackhole? Kind of river mill. (please forgive this naive questions!)