It's a bit of a strange idea from start to finish. The whole concept is, when you are about to go into a situation where you're likely to be raped, you just stick this thing in. So why not.... just turn around instead of going into the situation? How many people face rape risks that they're unable to avoid, but suddenly able to manage once the rapist has a dodad stuck to his penis? You can't get away before you're attacked... you can't defeat the rapist while he's subduing and undressing you... and then you're able to escape once the rape has been accomplished, you're at least undressed and possibly bound and unable to move with a newly / doubly enraged assailant right next to you? Rape is a crime about power and hatred of women, and there's real reason to think playing up castration anxiety isn't going to make a new friend.
There's a couple other questionable statements there--that there won't be any risk of STDs, which you can catch skin to skin (syphilis, herpes, warts, crabs) even if there's no "fluid" which is far from certain (at UVa, one sexual assailant was thwarted because the event was completed before it began, after which he fled). I haven't used many tampons (the site says the use experience would be the same), but given the purpose of this device one would imagine it would have to be larger. And the suggestion that you have this thing next to you at all times for rapid insertion in case someone unexpectedly raped you begs the question of whether there might be better last minute rape defenses and how many women want to live their lives on red alert all the time.
The most worrisome thing to me, though, is that most rapes are perpetrated by acquaintances (husbands, boyfriends, relatives, neighbors), and if you're in an abusive relationship and still at risk of rape, its because you are psychologically or practically (whether financially, or because of issues with the kids ro whatever) unwilling or unable to leave the relationship--so what will the aftermath of a fishhook condom attack be? It's STILL your word against his, since you could have used the condom in order to create false evidence of rape and extort / retaliate / whatever. I doubt it would be the ticket to safety the site says it will be.