<< What I want to know is where all that 10 million degrees went... I mean 10 million degrees is a lot of degrees. Even a few molecular fusions should have at least blown up their nail-polish-in-a-beaker apparatus, no? >>
You are referring to a particle temperature. A particle temperature is a measure of the energy of that particular particle or set of particles. In other words, in the supposed fusion reaction, a few particles reached 10 million degrees. One reaction has very little impact overall on the average temperature of the containing environment (in this case acetone).
What is needed is a plethora of fusion reactions or a higher "density" of reactions to raise the bulk temperature of the containing medium to a point of phase-change which then provides a potential for energy extraction that we consider useful. In this case if enough fusion reactions occurred, the acetone may be made to evaporate and then the resulting force of expansion due to pressure increase could be made to generate electricity.
One must be careful with nuclear experiments. Mistakes can lead to orders of magnitude differentials in expected output which can be quite hazardous to the surrounding environment...and those standing around in it. One does not simply immediately try to extract the maximum amount of reaction available in a medium. That leads to disaster. One tries to estimate and control reactions or one makes headlines in a bad way.
It is also possible to use high particle energy to perform other useful things. One example is found in the jewelry industry. A blue color in topaz is highly desired. If you subject lower grade topaz to nuclear radiation of a certian kind, it cause the topaz to change structure and become more blue. This is all done without translations of the energy to different forms (except inside the crystal structure of the topaz of course). The side effect of this process is that metallic impurities in the topaz become activated to some extent.
Perhaps a fusion reaction in acetone can produce effects other than direct production of energy even at a low level.
Nuclear polish remover anyone?