The only way I'm aware of is to use Theo's plug-in (addition) for SimPE:
http://www.moreawesomethanyou.com/smf/index.php/topic,8266.0.htmlThis removes all the clothes in the wardrobes, so you will have to re-obtain any you do want.
As with anything involving SimPE, it is always best (and cannot be stressed enough in its importance) to do a complete back-up of your My Documents--EA Games--The Sims 2 folder first (and store it someplace safe) as SimPE is a very powerful tool and does contain the potential to inadvertantly do things which might glork your 'hood or the entire game.
SimPE can be obtained here:
http://sims.ambertation.de/.