The physical experiences are very catalytical, and vary as follows:-

An itch, with no apparent source.

A fever, which causes the whole body to shiver for a few seconds.

The expansion of the selected fee point, over a period of four days, with three sleepless nights as the pain of the stretching skin increases to the point where the mind is tested considerably.

Then, when the boil bursts, and the fluid begins to flow in copious amounts, and the intense pain is removed, a feeling of lightness which is quite unusual, with the sure knowledge that the expelled fluid contained much bad karma from the past, and that a spiritual cleansing had taken place.

Then, when the fluid does not cease, but continues to produce a teaspoon full of fluid every hour, for several days, one realises just how much toxin/spiritual impurity we harbor.

The fluid starts as a yellow colour, and varies as drops of brown and red dye appear to be added occasionally. The overall consistency would be best described as watery snot. The cleansing continues.

I believe that the lymph gland system (immune system?) reaches a crisis point when the level of toxin reaches the upper level. A crisis cleansing is initiated, as described, and included is the process of growing a drain nipple, which is done with considerable pain, by stretching the skin under high pressure, and producing a blood free hole. When the nipple is sufficiently strong, the plug is blown and the flow starts.
 

Human Evolution: Clearing out the deadwood - developing the body - tuning the mind - accessing the spirit                    The Human Body