Clearing CGridView filters and sort orders from the web pages, is usefull for the end user. Yii does not seem to propose a standard method. Furthermore, this is especially usefull when filters are "remembered" in the user's session.
Yii Framework Wiki
Wiki articles tagged with "filtering"
Showing 1-4 of 4 items.
How to keep filters simple in CGridView
The problem is not new: after setting some filters in a grid (typically in admin view), and gone to another page, returning in the grid's page I would like to find the filters with previous setting mantained.
Displaying, sorting and filtering HasMany & ManyMany relations in CGridView
This tutorial gives you multiple options of how to fully implement showing, sorting and filtering related data in gridviews.
Intro
Displaying, Sorting and Filtering Model Relations on a GridView
One of the things you will find tricky to implement is the the sorting and filtering of a GridView's column that displays related model data.