Just like bleach, all chlorine based shocks add HOCl + -OCl once they dissolve. Do NOT use the non-chlorine shocks or the 'hodge-podge' multi-ingredient shocks, till you really know what you are doing, and are sure that that's what you want to do!

The difference between bleach, trichlor powder, dichlor granules, and cal hypo is what ELSE they add to the pool. The 'else' can be good, or bad, depending on what your pool needs. But bleach just adds salt as its 'else' -- so that's the simplest and safest option for you, till you have test results.