It can still be done and I just sent a box to Los Angeles from Bangkok. The restrictions I had to follow:

An unsolicited gift

Value less than  $100

It's really easy. You have to go to this website where there is a form to fill out your Thai address and the destination, plus they have a customs form where you list each item and the value:

https://dpostinter.thailandpost.com/

 

Print it out and take the paper along with the unwrapped items to the local Post Office. I bought a box there. The employees look through the stuff and then will pack the box, add bubble wrap, and then tape the box closed.

The one drawback is the expense. For a 24x40x17 cm box under 2 kg, my cost was 2,600 baht. Way more than the gifts were worth and I probably won't do it again unless sending something really valuable.

Thanks very much for posting this 😉

UPDATE:
The package was held up in Thai customs and returned. Two problems:

1. I included a bottle of body wash in it, and you aren't allowed to send liquids.
2. I included three of those herbal inhalers you see Thai people sniffing. You aren't allowed to send medication.

The post office called me yesterday and I went there today to remove the items. They looked through everything else, sealed the box, and said it should go through this time. No extra charge.

UPDATE 2:
The package was rejected again by Customs. After the previous rejection I had asked the Post Office if I needed a new customs form after removing the items and they said I did not. However, the customs department rejected it and said I have to create a new one.

I now need to go back to the Post Office with the new form, along with my passport.

 

UPDATE 3:

Rejected again. New problems:
1. I was sending packages of tea from Chiang Mai and listed them as "green tea". You are not allowed to send agricultural products.
2. I included two bags of My Chewy Taro candy and listed it on the customs form as "candy". This is too vague because candy can contain alcohol or other prohibited items.

The Thai Post Office employee, who was very nice and apologetic, said if it was labeled as Matcha or Oolong, then it would go through. However, Thai Customs requires the use of their online system which does not provide Matcha or Oolong as an option. The Postal employee said she would try to take care of it and I didn't need to go in again, so I guess she is manually writing Matcha on it.

According to ChatGPT, using "tea powder" might have worked because that wouldn't be considered "leaves" and so not an agricultural product.
But Perplexity.AI disagrees, and says "tea powder" is more regulated and would invite higher scrutiny. It suggests the "tea infusions" because that is how tea bags work and is more precise because it doesn't sound like I'm sending a bunch of leaves.

Perplexity said the online system is a simplified version of customs categories and the Thai Customs people are probably comparing my entries against the entire list of categories and thus rejecting it for vagueness.

They need to fix this. What if I was a tourist and sending things back to the US for convenience?