Answered by ZUPAN | Nov. 13, 2019 12:34
If I have properly understood, you plan to fly:
US - Hong Kong - Guangzhou - US
If I'm right and you don't have other some other stops, especially if you don't return to Hong Kong after Guangzhou, you will be definitely eligible for 144 hour visa free transit in entire Guangdong province.
Basically, you have two separate tickets:
US - Hong Kong
Hong Kong - Guangzhou - US
You will print out your second flight ticket and have that printout with you. After your stay in Hong Kong, you will declare at check-in in Hong Kong that you will travel to US via Guangzhou using 144 hour visa free transit. After a short inspection, you will be allowed to board the plane.
Upon your arrival in Guangzhou, you will approach 144 hour visa free transit counter where you will fill out the blue form, beside the yellow form that you will fill out in the plane between Hong Kong and Guangzhou. After that you will present your flight ticket and the forms. After a short inspection, you will get a sticker in your passport for free and be allowed to exit the airport and to explore entire Guangdong province.
72 hour visa free transit has been replaced in Guangzhou by 144 hour visa free transit in May of this year. Also, please, use correct terminology because it is 144 hours visa free (without visa) transit and there is no visa at all!