Every Bitcoin Cash is AFAIK also available in the Bitcoin blockchain. You could try:
1. Go to OmniWallet.org -> Create a wallet -> Fill all the fields and create your wallet
2. Go to "My Wallet" -> My Addresses -> Add Address -> "Import Adress with Private Key" and insert your BCH private key.
Please, what is AFAIK?
Sorry
AFAIK = As far as I know; Because I can't confirm that the information is 100% correct.
But anyway, did you manage to move your USDT by using the method I wrote above? If not, I would say that what OmegaStarScream said is correct.
I contacted Omniwallet and this is what they have to say; "BTC/BCH use same address/priv key space. So as long as you have the priv key you can import it into your Omniwallet wallet to regain access."
I sent the USDT to a BCH wallet provided by BTC.com and I have the backup seed for this wallet. My problem is I find it difficult to locate the exact address on the Github.io BIP32/39/44 Private Key generator tool because most addresses I see begins with 1 whereas the BCH address that holds the USDT begins with 3. That is, I see something like 1LgtXCuLq82yH4HGKmYtgjezVSP7ZCg6G4 instead of 3LgtXCuLq82yH4HGKmYtgjezVWP7ZCg6G4.
I have the Xprv*** which I believe is the Extended private key. However, Omniwallet doesn't recognize this. I'm stuck at moment.