Can one utilize the 9 kabin in the shower? How much water is it? How long does one have to shower to be yozei? How does it work? Can one shampoo and soap up after the 9 kabin has been done?
It seems that a shower is sufficient to fulfill the enactment of splashing 9 kabin of water.
The Gemara writes that this is effective a purification for somebody who saw a nocturnal emission, but not for somebody who actually had marital relations.
Some question the efficacy of a shower, because the shower head is connected to the wall (and therefore to the ground), and is therefore not a “vessel” (which is mentioned by the Gemara). However, the general consensus is that it is fine to use a shower for this purpose.
9 kabin of water work out to 12.5 liters (R’ Chaim No’eh) or 21.5 liters (Chazon Ish) – one can be lenient for this matter for the smaller quantity. For a regular stream, four minutes in the shower is more than enough. One can shower and soap after without concern.