A lot of women vomit after taking real ECP too, so I wouldn't necessarily blame it on the method, maybe it was just that particular brand.
As I said earlier, if you have a choice, take the real thing, but many women don't have a choice, so I wouldn't be trying to dissuade them from using this completely acceptable alternate method.
(Also, taking 2, then 2, then 2 is not the way it's recommended, women should check the chart.)