kohana framework, using Security:xss_clean in validation filters

I have this part of code:

    ->filter('username', 'Security::xss_clean')
                ->filter('url', 'Security::xss_clean')
                ->filter('text', 'Security::xss_clean')

but it not works and after validation parametres will be inserted via ORM into table co开发者_JAVA百科lumns with html tags. so, what i do wrong? or this method works only when writing output data, but not return changed value back to variable?

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Which variable are you using for the database input?

If your validation is like this:

$validation = Validate::factory ...

Then you will need to use:

$validation['url'];

instead of

 $_POST['url'];