Get all namespaces, filter by status Terminating, output the json, replace the finalizers with an empty set, then finally push the updated namespace's json representation back to the cluster.

forcedeletefinalizers.sh

for ns in `kubectl get namespaces | awk '/Terminating/ NR>1 {print $1}'`; \
do kubectl get namespace ${ns} -o json | tr -d "\n" | \
sed "s/\"finalizers\": \[[^]]\+\]/\"finalizers\": []/" | \
kubectl replace --raw /api/v1/namespaces/${ns}/finalize -f -; done;

for ns in `oc get projects|awk '/Terminating/ NR>1 {print $1}'`; do kubectl get namespace ${ns} -o json | tr -d "\n" | sed "s/\"finalizers\": \[[^]]\+\]/\"finalizers\": []/" | kubectl replace --raw /api/v1/namespaces/${ns}/finalize -f -; done;