From Hong Kong to Guangzhou. Ann

Yes.

Your trip would be: Hong Kong - Guangzhou - Hong Kong.

As you see Hong Kong is before and after Guangzhou but it should be different.

An alternative to get the free transit would be: Hong Kong - Guangzhou - Macau. (from Macau take the ferry to return to Hong Kong).

One condition here is to land at the airport of Guangzhou then go in Macau with prepaid flights on the same itinerary. It that exists ... if would be too expensive for only 1 day.

If you didn't yet visit Macau that would be a good choice for around $40/return. But get ready to walk a lot. No hostels in Macau.