No that does not work. The solution posted by P-DEX is the only way I have found to get rid of the factions in question. The delete selection no longer works at all for any in game faction, even those made by you and not D/L to the workshop. If the unwanted faction was subscribed in the workshop just un-subscribe and it is gone. My problem was that the factions I wanted to delete had been removed from the workshop, so I could not unsubscribe. This would probably be a rare occurrence, but if it happens, deleting from your My Docs faction files and from the Steam workshop files, will remove them.
I am not sure what is going on with the delete function not working in 1.1 any more. I assume yesterday's patch has something to do with it. If you are just deleting a personal race creation that has not been sent to the workshop, deleting from your docs file is not that hard, but I'll bet that if delete isn't fixed for the formal release of 1.1, some people will be unhappy.