The only thing that really works for me is Veet.
This is mostly, I suppose, 'cause I have really sensitive skin. Shaving is ok the first day, but after that I am in extreme pain and have a horrible rash for a few days. I always seem to get ingrowns afterwards, too.
Waxing is just too painful and leaves me red for several days.
I've never had a problem with irritation with depilatories, and they seem to keep the hair away for a satisfying amount of time. I actually like Nair better than Veet, but I don't know if that's sold in the UK.
If you dislike Veet because it doesn't get rid of all the hair, I'd go for a professional wax. It shouldn't be red for more than a few hours/overnight. It definitely discourages ingrowns, too. You should be good to go if your skin isn't as temperamental as mine!
Have a good holiday!