Don't waste your time. The bitcoin chainanalysis companies have software that can see past mixers now, and have for some time. If you rely on a mixing service to anonymize your bitcoin when it comes time to cash out you may get a surprise. If you have bitcoin you need to anonymize you have to swap to an anonymous coin like Monero and back. The authorities hate Monero because they can not pierce the veil of that blockchain.
A good workflow could be:
activate vpn
create an online monero wallet
change btc to monero with changelly.com
create some more online monero wallets
send monero from 1st wallet to them
wait some days
create a btc paper wallet
change monero to btc with cryptonator.com
someone should create an online service for that using their api.