Wordpress - Will it break my site if I delete all transient records in wp_options table?

I used:

DELETE FROM `wp_options` WHERE `option_name` LIKE ('%\_transient\_%');

to cleanup with great results :)

(from here https://stackoverflow.com/questions/10422574/can-i-remove-transients-in-the-wp-options-table-of-my-wordpress-install)

This is a fairly definitive set of responses about transients

WPSE: Are transients garbage collected?

Here's a simple function to clear all transients and timeouts - add extra to fit your needs.

    function clear_transients()
    {

        global $wpdb;

        // delete all "namespace" transients
        $sql = "
            DELETE 
            FROM {$wpdb->options}
            WHERE option_name like '\_transient\_namespace\_%'
            OR option_name like '\_transient\_timeout\_namespace\_%'
        ";

        $wpdb->query($sql);

    }