Most of the force of the pressure will be used in unwrapping the pipe if you don’t have a powerful pump the pressure at the end will be too weak.Unfortunateley the silicone tube inside gets destroyed easily after short period.Had one thirty years ago. Self destructed forth use.That knot you made was made so that it would untie though.I bought one of these hoses a few years ago for my husband. And it has been the best hoes we have ever had.I was first counfused when it was becoming large and moving.