Or you could plan ahead. Have your relatives speak with the people at Jaben HK/GZ and find out if you can have an audiologist in your current country of residence do an impression for you. Then you ship the impressions/molds to your relatives (or directly to Jaben). If all goes as planned, you can walk into Jaben during your visit to pick them up. That way, you can test them out in the store. I know of some people from Europe who've done the same via the Jaben in Singapore.
Thing is I wanted to demo them first before I ordered, it would take no time at all to send my impressions and order over before my visit and just pick up the customs when I get there but I'd be stuck with them if I didn't like what I was hearing.
Thanks for the tip, prices in mainland were usually higher than HK.