mixing is a process with a 1000 transaction in once but did they really anonymous? the answer is no if someone just have some small skill 7 they really want to track you they can easy done you because (BTC,BCH,LTC,ETH,ETHC,TRON,USDT,ETC) all of them are have a public blockchain & every transaction are recorded on the block size .
so you have only 1 option which is (Monero & Dash & ZCash) but dont make a mistake also for all of this guys you need use a hardware wallet with your own blockchain node to make yourself 100% anonymous otherwise take your own risk.
for exchange never use direct exchange like ( binance, bybit, okx) make sure you put all your coin in your hardware wallet for morethan 3 days why 3 days because in this 3 day more than 500 monero coin or dash are mined so the layer of her blockchain or node get a really impossible to find all block size & her hash so as i say make sure you put in hardware wallet for 3 days then swap him to (Dash) then after dash swap him to usdt or other normal crypto