I just tried the old trusty esbit stove tonight. I learned a couple of lessons...

** Lesson One **
I tried to light the fuel with the old magnesium block...
Sparks alone will NOT light the fuel.
Magnesium and sparks will not light the fuel.
Igniting 1/2 cotton ball on top of the fuel also failed.
Lighting 1/2 cotton ball and dropping the fuel on top worked fine. It left a heck of a mess on the stove, though.

** Lesson 2 **
I used enough water to fill two coffee mugs in a small stainless-steel kitchen pot. The water got hot enough for a nice cup of hot chocolate, but that is it. I saw some small (pinhead size) bubbles, and a bit of steam. Good enough for eating, but not hot enough to kill much.

It it possible that it might have boiled a smaller amount. I have not tried it yet. Plus, esbit fuel is hard to find around here (unless you buy a whole new stove).