If you use getCache with custom cache partitions, and you want an easy way to manually refresh that cache from the manager, you can quickly add a custom Menu that does just that using the connector and processor that comes with getCache (since v1.1.0).

First, create a new Menu in the tree at System --> Actions in the MODX Manager. I recommend creating these custom Menus as children of the Site --> Clear Cache menu. Give it a unique Lexicon Key and Description, select No Action for the Action, you can reuse the images/icons/refresh.png for the Icon, and leave Parameters empty. In the Handler field, you can provide Javascript similar to the following example, which would be used to refresh a cache partition called global_cache:

var topic = '/getcache/cache/partition/refresh/global_cache/';
this.console = MODx.load({
    xtype: 'modx-console'
    ,register: 'mgr'
    ,topic: topic
    ,show_filename: 0
});
this.console.show(Ext.getBody());

MODx.Ajax.request({
    url: MODx.config.assets_url+'components/getcache/connector.php'
    ,params: { action: 'cache/partition/refresh', partitions: 'global_cache', register: 'mgr' , topic: topic }
    ,listeners: {
        'success':{fn:function() {
            this.console.fireEvent('complete');
            this.console = null;
        },scope:this}
    }
});
return false;

Just set a unique topic variable and change the partitions sent in the params object of the MODx.Ajax.request() call.

Finally, you can give the Menu a Permission (or comma-delimited list of Permissions) required to see the Menu. The processor itself requires the empty_cache Permission.