This is a great gag. I carry one in my pocket all the time.
Picture this your sitting at the dinner table and you take out the container and explain that you were asked for a stool sample. You explain that this might not be the best time to bring this up, but it is important to you that you have done this the right way. So you ask / insist that your friend at the table take a look to make sure it is a good sample. BTW it is even better when you give it to your doctor!
Thanks Farvel the Marvel wish you were still with us.