I've been harbouring your idea of "18th Cenury" punishments for along time, and think it's an excellent idea. For those convicted of violent crimes, a certain number of lashes with the birch would be a good detterent. I also think the stocks should be brought back, especially good for things like fraud, muggings etc, where the perpetrator could be seen to be shamed. I believe if there were more shaming, it would act as a massive deterrent, and so much cheaper than prisons.
Also, people complain nowadays about the drugs problem in prisons. Simple. If there is a drugs problem, ban visitors. Or only let them visit and see the prsioner through a perspex screen, like in america.
Boot camps in prisons are another thing I'd like to see. More of a DETERRENT!