Hi Rose
I am with Bob on this one. I wouldn't dream of doing a long haul flight without wearing flight socks. I don't think it's worth the risk by not wearing them. I wear the Scholl flight socks, I think Boots have their own brand. They cost around £13 a pair but once you have them it is a capital investment because they will be there for your future JY holidays. You may well become addicted to JY, as many of us have!
I take the small aspirins,too, as Cindy mentioned.
I don't always have time to reply to posts but I think your post regarding compression/flight socks is extremely important as it concerns a serious health issue.
I went to Vietnam in 2014, loved it, didn't do the Cambodia add-on but a friend who did preferred Cambodia. Of the 18 or so in our group who did the Cu Chi Tunnels only one person went down them.
Enjoy your travels
Kind regards
Di