Do you mean nudge a comet closer to the sun? The H2O would just boil off and not be recoverable on Titan, would it? And you still need to separate out all that H and O.
1. I am picturing removing hydrocarbons from Titan, say with a space elevator (much more practical out there where a broken cable would not be such a target for muslim savages).
2. Capture steam or (just recover liquid water) from asteroid, or perhaps cut to the chase with O2/O3 if found. I agree some sort of cracking of h20 would be needed if only water could be found, probably solar or heat generated electric -— the reaction between O2 and any given hydrocarbon being considerably more energetic than with hydrogen.
Specifically, at any pressure, hydrogen gas carries less energy per volumethan methane (typical natural gas). At 800 bar pressure gaseous hydrogen reaches the volumetric energy density of liquid hydrogen. But the volumetric energy density of methane at 800 bar is higher by factor 3.2. The common liquid energy carriers methanol, propane and octane (representing gasoline) surpass liquid hydrogen by factors 1.7 to 3.4, respectively.
But at 800 bar or in the liquid state hydrogen must be contained in some pretty fancy stuff.
In short, this is a lot of potential energy found out in space where it can be gotten.