Currently about 20% to 30% of hash power is running full-rbf – notably AntPool – so you no longer need to set nSequence. Just set mempoolfullrbf=1 in your bitcoin.conf on a well-connected Bitcoin Core node and publish it. You can also publish it via https://blockstream.info/tx/push and https://mempool.nixbitcoin.org/tx/push both of which support full-rbf.