Hi,
if you need to clear delta queues means you need to load all delta data from source to bw and keep all queues as 0.
at RSA7 check your data source total column need to have 0.
for safe side we need to keep all delta queues as 0 and lock source(ECC) system.
Later do your transports. once your TR successfully without any issue then unlock ecc system and continue with your delta loads.
Thanks