OK, so Clark is vulnerable to certain things - all the varying colours of Kryptonite - but he's never been vulnerable to the same things as others in the same way.
Suddenly up pops Barbie from nowhere in particular for no particular reason and suddenly just one little word and Clark's anyone's!? It's not even clear that it's red kryptonite in there until the end, and even that wouldn't have the same effect. It makes him bad and rebellious because he wants to be - not controlled by hypnosis.
There are too many plot holes, many of which are included in the notes and trivia. The differences in time, the fact that he's not supposed to have had sex with this woman despite the taking off of as many clothes as they could get away with on prime time.
And why doesn't she reveal his secret? To anyone? How could Lex hope to control her if she's really able to control him at the drop of an amulet? And since her abilities seem caught up in the necklace, why is she so great at hypnosis. Shouldn't it be one of the meteor rock abilities that she's gained or something vaguely believable?
The only rather fun part is Clark knocking Lois out by flicking her head with his finger. The episode needed much more of this kind of insight and humour - or needed a real dark side to it.
It seems obvious to me that the writers were looking for a way to break up Clark and Lana. Unfortunately, now the series has continued (which I'm really glad about), it's becoming obvious because of the Superman legend that Clark and Lana are never meant to be together, so they had to find a way of making sure they aren't. I just think it could have been so much better handled than this very wimpy episode. I haven't watched the final episodes in this season yet, so I'm hoping that this is the last time we'll have to sit through the friends/lovers/enemies/friends/lovers/in-love/broken up/ not quite sure where are now kind of stuff that they've put us all through for the previous seasons. Yes we wanted them to be together. Yes we know they can't be. So stop simpering the pair of you and get a life!
There was such potential here for a great ending to the romance, but I truly believe the writers botched it big time.