Every manager will buy his fair share of clangers and obviously Houllier had his fair share. Some of the players that he bought were pretty garbage and there are some real obvious ones. I think that though for the money that he spent (and remember he was buying players when the transfer market was going mental with players being vastly overvalued) was pretty reasonable.
And some of the signings that he "made" were actually ones that had been pre-arranged by others so he can hardly be blamed for them.
Also he didn't actually sell McManaman but rather the midfielder decided to leave on a free transfer when his contract expired. One of the reasons that Liverpool sold Michael Owen was because they were afraid that he would leave under the Bosman ruling and the club decided that they couldn't afford to let that happen.
Some of the signings that GH made were top drawer except for Harry Kewell of course who at AUD1.50 would be overpriced.