Precab: how do you know you actually need that weekly shock? You may simply have a very high (but perhaps unnecessary) factor of safety. I understand your reluctance to not shock - if, for some reason, your pool is on the edge of algae outbreak, but you can't see it (or you don't have the test results for CC), you may not want to experiment, get an algae outbreak, then have to work harder to get ahead of it. On the other hand, you may be spending money on chemicals unnecessarily.
If one doesn't have accurate test results, the CYA level is unknown, or if the pool liner and/or filter is harboring lingering algae and other organics, I can see why the overly conservative weekly shock approach is recommended. And, as pointed out throughout this web site, if they CYA level is very high (> 100, for example), then a whopping dose of chlorine may be necessary on a regular basis.
I have been running our pool for over a month with only one elevated chlorine treatment - during the second week after opening , the chlorine level got to the low side for a couple of days, the water was becoming cloudy, and the CC was right at 0.5. I raised the chlorine level up to 12, and it gradually came down to 6 or 7 in a couple of days, water cleared up, CC is non-detectable, and chlorine is maintained between 3 and 5 (CYA about 40). I have operated the pool at the recommended FC range for the CYA level for more than 3 weeks, and through heavy bather load of 4th of July, 3 weeks of high humidity, +90 degree heat, and the water is crystal clear - no shock during this time.
Anyway, that's my 2 cents-worth.