Man of Honour
Can't you run some clean TT sessions and get out of Rookie that way?
You can, but the SR gains are very small and it would take a lot longer than completing clean races.
As many have said before, start from the back or the pits and concentrate on being clean and avoiding accidents. It's a bit harder to do on the ovals because you should only be racing on the large oval, every other week. But also because on the large oval there's no braking involved and so the racing pace is very high compared to road races and therefor it's harder to avoid accidents. On the small oval track there are too many cars and not enough track and brains to make it anything other than a crash fest most of the time.