I confess to being another Mooncup user so if anyone has a question they don't want to post here then please pm me.
The have very tiny holes in the cup part, much too small to let anything leak but they are what breaks the suction. However the holes can get clogged, so that is when you would use the pin NOT when it's inside LOL! You actually get used to twisting it slightly and out it comes, because it's a cup it's relatively easy to hold upright. For those that have the <ahem> 'clopped liver' problems it's easier than a tampon which on removal can be like a dam bursting! I also think it's less painful but I have had occasional leaks while getting used to it so I'd only wear it at home initially. The main problem is using it at work with no sink handy and relying on just wiping it, I much prefer rinsing it out. You only need to sterilise it once a month. There is even a Yahoo group to discuss the 3 main types of cups and they have answers to EVERY question you could imagine. Yahoo groups
Pam