If asked whether USDT can be mixed? It is best to clarify the question first. USDT cannot be mixed with other coins unless you exchange it first on an exchange, otherwise I don't know. The question is why do you intend to hide it, because the value is too great or maybe it belongs to someone else, sorry. Comply with your country laws or regulation when you register exchange. Even if you later want to exchange USDT for XMR. Some popular platforms that allow this include Binance, Kraken, and KuCoin. Yes, almost all of them do KYC.