These definitely do as they are meant to do.
I would recommend them for people who are going camping with a large group or with many young girls or women. They are great to have on hand for females who are worried about being too low to the ground where the snakes and spiders could be! They also make it so much easier for women to relieve their bladders quickly and discreetly. I took these on a big camping trip and my friend and my daughter and I all found them to be a great addition to our camp kits!
If you are purchasing this item for yourself only and not just as an item to have on hand for other campers in your group, I would suggest going with a higher quality choice for a better close up fit that is made from a higher quality, more flexible, silicone material. There are great options out there for single individual multi-use funnels.
Though I do suggest going for a different brand for self-use, I do think these are a great low-cost option to have for others who may need one on an outdoor adventure. They do work and are quick and easy to clean. They, however, are not very flexible and don't pack up in a hiking bag as well as other options out there do. I'd personally only use these for camping trips or emergency situations where there isn't a restroom nearby. I wouldn't take these in a hiking bag. Also, they really could fit better and more flush against the skin but they don't so that's a negative for me. I luckily had no issues with leaking on to my clothing or anything but I could see it easily happening to a woman or child who is using this type of product for the first time.
Good luck with your shopping adventures! I hope that this helps someone to make a good purchase!