I haven't but do know that it can be done, but to be honest would recommend it as a good way of acquiring a rose bush for the simple reason, that it can take at least 3 - 4 years before it would become a rose bush, the size of the ones that you see in the nurseries and also for all the effort involved, you are highly unlikely to get a rose that resembles the mother plant.
The best way to propagate a rose is to take stem cuttings and insert them into the ground and if done at this time of year, by the time spring arrives you will have the beginnings of a rose bush
But should you want to try growing a rose from seed and you live in a warmish climate - now is the time to do it, but first you will need to separate the seed, which is done by first soaking the rosehip in water overnight, after which you will need to remove and discard any seeds that are floating on the surface, before tipping out onto a board for the next very fiddly stage of trying to separate the remaining seeds from the pulp with a stiff brush, which can be quite time consuming and as I said extremely fiddly, but once done you can sow the seeds immediately.