diff --git a/README b/README
--- a/README
+++ b/README
@@ -24,7 +24,7 @@
 To export up-to-date strings from Phabricator, run:
 
 ```
-$ ./bin/translatewiki export path/to/phabricator --project phabricator
+$ ./bin/translatewiki export path/to/phabricator/src/ --project phabricator
 ```
 
 This will update `projects/phabricator/en.json` and related files.
@@ -38,10 +38,10 @@
 
 ```
 $ ./bin/translatewiki generate \
-  --source path/to/your/strings.json
-  --class YourLanguageTranslation
-  --locale xx_YY
-  --project phabricator
+  --source path/to/your/strings.json \
+  --class YourLanguageTranslation \
+  --locale xx_YY \
+  --project phabricator \
   --out path/to/YourLanguageTranslation.php
 ```
 
diff --git a/src/management/TranslatewikiManagementExportWorkflow.php b/src/management/TranslatewikiManagementExportWorkflow.php
--- a/src/management/TranslatewikiManagementExportWorkflow.php
+++ b/src/management/TranslatewikiManagementExportWorkflow.php
@@ -28,6 +28,12 @@
               'Base URI for browsing files in the project being exported.'),
           ),
           array(
+            'name' => 'clean',
+            'help' => pht(
+              'Pass --clean to the underlying extractor to drop caches '.
+              'before extracting strings and do a full clean rebuild. Slow!'),
+          ),
+          array(
             'name' => 'library',
             'wildcard' => true,
           ),
@@ -67,9 +73,15 @@
       "%s\n",
       pht('Extracting library strings...'));
 
+    $extract_args = array();
+    if ($args->getArg('clean')) {
+      $extract_args[] = '--clean';
+    }
+
     phutil_passthru(
-      '%R extract %R',
+      '%R extract %Ls %R',
       $i18n_bin,
+      $extract_args,
       $export_root);
 
     $strings_path = $export_root.'/.cache/i18n_strings.json';