Interesting, how the OP asked basically about getting a Farm jack / Hi lift, call it what you will, as he cannot justify a winch.
Yet some of the responses seem to be screaming about how dangerous they are to use for lifting the vehicle. Without answering his origiinal question.
In answer to your original question, they can be used to winch the vehicle as you have obviouslyy seen on You tube, but it will take time and making sure it is correctly attached to the straps you are using etc is obviously important. It wil require resetting every time it has run out of stroke, Plus remember you will still need something to anchor to. Maybe just for winching a " tirfor " style will be of more use to you.
As you may have read above, using them for lifting the vehicle can be tricky and you need to pay attention, have the proper equipment and technique. Even then maybe a hilift / farm jack is not the most appropriate to use for jacking. It is a tool that has uses it is your job to know what is the best use of it safely.
Cheers