Russ,
Your quality of life just jumped tremendously--isn't it great!
To me, length of soak is purely personal with the only influence being how hot one keeps the water. I keep mine at a temp that allows me to stay as long as I want without having to get out or use the cooldown seat--100F now in winter and 96F in summer. Seems like I'm at the lower end of the totem pole around here as there are many more that prefer 102+.
Chlorinating is the same to me as sanitizing with dichlor as opposed to shocking with either dichlor or MPS. Sanitizing includes adding sanitizer to the water for the purpose of killing bacteria and the like. Take using dichlor as your sanitizer, for instance. The sanitization process takes free chlorine and combines it with the bacteria, effectively killing the bacteria, to form combined chlorines or chloromines--basically 'spent' chlorine. These chloromines will stay in the water until shocked or oxidated. The shocking process effectively oxidates or burns off the chloromines so that the only chlorine left is free chlorine--chlorine that is ready to kill. Bromine works similarly.
Hope this helps--
