Simple utility script to remove all undesired context and associated resources from modx db

modx.batchRemoveContexts

$dontRem  = array('web','mgr'); /* add any additional context you dont wish to have removed here */
$contexts = $modx->getCollection('modContext');

foreach($contexts as $ctx){
    $key = $ctx->get('key');
    if(!in_array($key,$dontRem)) { 
        $response = $modx->runProcessor('context/remove',array('key'=>$key));
  	    if ($response->isError()) {
		        echo $response->getMessage() . '<hr/>';
		    }
		    else{
		        echo "removed $key";
		    }
    }
}