There are some instances where the only answer to the style corruption
is to delete the style (and alter document formatting) or or save as
xml.
For all other cases, I use a macro that relies on Cindy Meister's
code, but allows the target style to be selected by the user. The vba
code is posted on my blog:
http://vbaforword.wordpress.com/2009/05/23/remove-char-styles/