I use a SM-500 which has both multiplex and flash, and presets for it the same as a senior does.Having recently done a lot of work in thermolysis for both I can give you some feedback though certainly not as much as someone who has worked in these modalities for years.I can give you some feedback though.
First, I want to say having switched back and forth between modalities quite a bit, that in some areas of the body, the multiplex settings and flash settings are virtually identical in some cases but with different timing.An example would be for arm hair, the presets have for course arm hair a setting of .08 seconds flash at 88% intensity. Multiplex has a single pulse, of identical intensity and duration.So what is the difference? Timing and this affects accuracy. Thicker hairs may use 4-5 pulses, but the difference is in how that energy is delivered.
Whether flash or multiplex, I generally end up increasing the settings . With a .08 pulse that gets increased to 0.09 and 90-92 % intensity.However with flash, that pulse is delivered as soon as I put my foot on the pedal. With multiplex single pulse, it is almost a full second before the pulse is delivered at the end of the cycle.
Typically if working on courser hairs I deliver 3-4 pulses, at either 9 oclock 3 oclock ( then pulled out slightly to destroy the bulge) or at 12, 4 and 8 oclock and then the bulge depending on releases. This helps to deliver the energy to the right part of the follicle.The energy dispersal area is relatively narrow.With flash, I can accomplish this in something under 1/2 a second. Because of the delay with multiplex, this same task takes 3-4 seconds to accomplish.
Now with multi-pulse multiplex, the energy is delivered , lets say I program multiplex for 4 pulses of .90% .09 seconds. These 4 pulses will be spread evenly over about a 1 second to 1 1/2 second period. Additionally, I may not have the probe exactly where in the follicle I want it when the energy is delivered. For this reason, for me at least both accuracy and speed are better with the flash.Itās all about control and timing.
For effectiveness, I still like the multiplex blend but having tested both flash and blend on the genitals, I think blend is too painful for that area, at least for me. I recently got to see a client who had paused for 6 months her treatment. I had treated her almost entirely with blend. I was delighted to see that 6 months later, it was clear my blend was reaching about a 90-95% kill rate. I dont have as much confidence in thermolysis to produce the same results, but perhaps I will have another client pause similarly and Iāll be just as happy with the kill rate but at the moment I dont have confidence this would be the case. Itās definitely faster than my blend however.
Seana