only problem with doing this with an agent is its illegal and if you were to be unfortunate to be on the other side of the police and they looked at your file or your agent was investigated you could have it revoked and given a ban from Thailand. My motto.
If you can’t do it then you can’t afford to live in Thailand
they have arrangements with banks to show the money in their accounts. Also give a qualifying letter to say it’s from overseas. The same hr the money goes back. I saw an agent facilitate this in Bangkok bank last month