Thank you for your advice. I do have a difficulty though because if I am not right next to the toilet, I would have a mess all over!
I have not been able to "hold the water (with coffee or plain water)" in me long enough for it to be effective. What comes out is just the water...mostly. One time, I was able to hold it until all the water entered me, then I could not hold it longer. So, do you have suggestions on that? I will look at links you refer also.
As for a baby bath therometer or (baby anything :-)), nope. My 'baby' will be 19 this year.