LOL!! 
Thanks for the Googling! Not real sure if I understand it but...I will ponder it for a while. 
Not sure if chlorine lock really exists. In outdoor pools and spas, chlorine will be depleted quickly by the sun (chlorine's enemy). Cyanuric acid, aka CYA, aka stabilizer is used to protect or shield chlorine from the sun. CYA is either added separately or is introduced to water using a stabilized chlorine. The two stabilized chlorines are trichlor and dichlor. The ideal level of CYA is 20-50 ppm. Above those levels, CYA starts to inhibit (overprotect) the sanitizing ability of the available chlorine. The use of stabilized chlorine will continually add to CYA levels. The only way to reduce this level is to replace some or all of the water.
The higher the CYA level, the higher free chlorine level is needed to reach the same sanitizing power. Free chlorine level at 40 ppm stabilizer would need to be higher at 80 ppm stabilizer to do the same job. There are charts showing the amount of chlorine needed at different CYA levels. There does seem to be a top end where stabilizer has no more or diminishing effect on chlorine.
Dichlor is used in portable spas for two reasons...it is quick dissolving granules and it is nearly pH neutral (slightly acidic). Dichlor also adds stabilizer on a nearly one to one basis. Most spas sanitized with dichlor will build to well over 100 ppm CYA by the time the water is changed, most without noticing much difference. At three or four months when most are ready to change water, there are many forces diminishing the quality of water.
