Of course, certain substances should only be handled by lisenced vets (otherwise "peaceful release" can be uncertain or actually quite painful...). Some people do feel the same way this lady does about euthanisia being done at their homes. Many vets will do housecalls for this sort of thing.

This article has a section on "home euthanasia" (done by a vet).

http://www.thepetcenter.com/imtop/euthanasia.htm

All pet owners want their pet's last moments to be as comfortable as possible and as stress free for themselves and their pet as the situation can be. The natural question is "Can the veterinarian come to our home to administer the euthanasia solution?" The answer is Yes. However, there are a number of things for you to consider.
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There are veterinarians who have made it a policy never to euthanize a pet outside of the animal hospital setting. They have some very good reasons for this policy. However, if you must have your pet euthanized at home, don't be reluctant to make some phone calls and you will be able to find a veterinarian who will accommodate your wishes.