Aliso Creek trail? I can see where the terrain around Mission Viejo might be challenging.
I think the better way to improve on hills, rather than grueling long rides, is shorter, higher-intensity ones. Or Intervals. Basically, ride hard until you're done-in, then quit for the day. And by "done in" I mean you're not recovering from an all-out effort. Sort of like a weight lifter working a muscle group to failure. Two or three times, max, then quit. Extending the agony out isn't helping.