Modalities refers to the means at which hair folicules are killed. Galvanic works by using a DC current to convert moisture into lye, so it works by Chemical Distruction. Thermolysis (slow) works by generating heat in excess of 127 deg F. This temperature causes coagulation. Next is the fastest modality being Flash. It uses a higher RF current and generates heat in excess of 212 deg F. This causes desication of moisture from all cells in the immediate vacinity of the probe. You may have heard of blend as well. Blend is a mixture of Galvanic and Thermolysis, with just enough heat to make the lye better able to get into small spaces. The RF level for blend is very low, and it works on the same principle as Galvanic, only does not take as long.
The one touch is strictly galvanic, and unless your hair folicles are rather large, the probe is not going to fit. It is a size 10. I generally use a size 3 to 5 in my electrolysis practice. There is a link in the Do it yourself section that discribes how to build your own galvanic epilator similar to the one touch but that can use professional probes and is much more reliable. You might want to consider that route as well. I am working on a homebrew 27mhz flash epilator but I am still very much in the design stage yet on it. Taking a CB radio and converting it to a professional epilator. If you can afford to purchase a couple of electrolysis books, it would serve you well, especially if you are considering performing electrolysis on yourself and also with a buddy.
For large surface areas, galvanic is extremely slow. Taking about a minute or so per hair. Blend is faster being 6-8 seconds per hair. Slow thermolysis is again faster with being tenths of a second, and Flash is in hundredths or thousandths of a second. As time decreases however, skill becomes just that much more important. Galvanic is very forgiving, and Flash requires great skill in probe depth placement.
I hope this information helps you.
Martha Montgomery, CCE
Puget Sound Electrology