diff --git a/openupgradelib/openupgrade.py b/openupgradelib/openupgrade.py
index cae812e7..da5c29d3 100644
--- a/openupgradelib/openupgrade.py
+++ b/openupgradelib/openupgrade.py
@@ -194,6 +194,7 @@ def do_raise(error):
     "convert_to_company_dependent",
     "cow_templates_mark_if_equal_to_upstream",
     "cow_templates_replicate_upstream",
+    "clean_transient_models",
 ]
 
 
@@ -3492,3 +3493,29 @@ def cow_templates_replicate_upstream(cr, mark_colname=None):
         """
         ).format(mark_identifier),
     )
+
+
+def clean_transient_models(env):
+    """Clean transient models to prevent possible issues due to
+    chained data.
+
+    To be run at the base post-migration script for having a general scope. Only
+    assured to work on > v9.
+
+    :param env: Environment/pool variable.
+    """
+    for mname in env:
+        model = env[mname]
+        if model.is_transient():
+            try:
+                with env._cr.savepoint():
+                    table = sql.Identifier(model._table)
+                    query = sql.SQL(
+                        """DELETE FROM {} WHERE
+                        COALESCE(write_date, create_date, (now() at time zone 'UTC'))::timestamp
+                        < ((now() at time zone 'UTC') - interval '1 seconds')"""
+                    ).format(table)
+                    env._cr.execute(query)
+                env._cr.commit()
+            except Exception as e:
+                logger.warning("Failed to clean transient model %s\n%s", model, str(e))