Why should I start with only one and a half minutes, if I can start with more?

The directive is intended to prevent the increase of pain, in cases where  an inflammation has developed. If, after a one-and-a-half-minute treatment, no increase of pain is felt, it is recommended, for the following treatment, to go up to the full treatment protocol of six minutes, twice a day. If pain is felt, then the length of the treatment should be increased gradually, by approximately one additional minute per day, for each spot to be treated, until the full duration is reached.