Transferwise is ok as long as your receiving bank is Bangkok Bank and 2 others. Otherwise it goes to their main three banks in Thailand and is passed on to the secondary final bank. This means there is NO foreign transfer down in b acct
From my experience last year. Just forward the bank statement for 3 months signed by the bank showing your account. No need to keep money in after acceptance. I did my by post and was returned in 5 days.
Just a note. Buy a e Visa for Cambodia on line. Quick and easy 37 dollars and you do not get a whole page wasted in the passport. Plus Poi Phet is best done after 15.30 otherwise you queue for 2 hrs.