Can I use an agent to obtain a police clearance certificate instead of going to Bangkok?

I think it depends on what document/evidence you show at the clearance center that requires you to get a police clearance. For example: if you have a document that shows you are getting an interview at another embassy, they will use the interview date as the date they need to process and complete your clearance paperwork. Note - be sure to request the completed clearance about 5 days in advance if they mail it to you somewhere in Thailand. Or request to come back and pick it up...that's what we did. It's one sheet of paper, specific to the country/etc that requires you to get a clearance. I suggest to get their mobile number so you can call to check status about 7 to 10 days before you need it. (this is what we did 2 weeks ago in Feb)