i fly to manila from belgium first april like to use to 72 hours visa for a stopover in Guangzhou

i fly from belgium to manila first april , like to use the 72 hour service for a stopover in Guangzhou , on my way back to Belgium , like a stopever for 72 hours again in Ghuangzou, will this double entry cause any problems . of course all my ticktets r booked at the same company and i have my ticket to belgium, will confirm it ol ? can u pls give me a decent answer , cause nobody seems to know , thanks in advance