Change the tub.
I keep a tub that has been properly mounted at least once wrapped in cling film. So I rip the old one off & then mount the new one & get it up to pressure. As long as you use a tub that's been properly glued once there's enough tac on the glue to keep the tyre on the rim as long as don't star trying to really throw the bike about. It's good enough for TTing but I'd not want to go road racing on the tyre.
It's probably as good as a tape job anyways, and loads of people race taped tubs.