Addendum: Also, either Passbook Savings or Fixed Deposit is Ok (but not Investment Accounts). But, all above, should be differentiated from the Income Method -- which, definitely does require proof of foreign funds origin, and regular monthly deposits for prior 12 mos. (ie. A "Big Pain in the Arse").
Tod is absolutely correct. My wife and I just did it in CM. No Seasoning required for initial 90-day Non-O, and No Proof of origin of money, just so long as it is deposited in Thai Bank. AND, also note it IS OK (esp. for husband and wife) to use a JOINT ACCOUNT -- of course, that requires double the money i.e. 1.6 Mil. Baht.