“boost your mileage with water” I want to hear from the poor shmuk that it didn’t work for. Not it can’t work

HalleluYah!

I’ve heard a lot about these “water from fuel” or “boost your gas milage with water” and now I have a question;
Can all of you who tried these things give a report?
Yeah, yeah, I know according to thermodynamics it’s impossible. Here’s what I’m looking for and I’ll say it somewhat bluntly. I want to hear from the poor shlep who bought one of these things and it didn’t work. I searched some, but it seems that most of the claims aren’t gained by experience.

Thank you for your time!