Implemented Martin's suggestion to clear the free lists during the garbage collection of the highest generation.
diff --git a/Doc/c-api/unicode.rst b/Doc/c-api/unicode.rst
index 7c570ab..5e5d1a2 100644
--- a/Doc/c-api/unicode.rst
+++ b/Doc/c-api/unicode.rst
@@ -89,6 +89,13 @@
    Return a pointer to the internal buffer of the object. *o* has to be a
    :ctype:`PyUnicodeObject` (not checked).
 
+
+.. cfunction:: int PyUnicode_ClearFreeList(void)
+
+   Clear the free list. Return the total number of freed items.
+
+   .. versionadded:: 2.6
+
 Unicode provides many different character properties. The most often needed ones
 are available through these macros which are mapped to C functions depending on
 the Python configuration.