When we take medicine, we do not see what changes occur in the organs. In the same way we do not see what changes occur in our system of subtle body, chakra’s, nadi’s while acting moral and immoral, mentally, verbally and bodily, but changes occur. At least that’s what i understood.
Like we can talk about changes in the brain due to certain behaviour or kind of thinking , in the same way, traditionally, is spoken about changes that occur in the subtle system of chakra’s etc. due to our activities, way of thinking etc. I am not an expert in this but i think this kind of knowledge is special.
Practising buddha-dhamma leads to changes on this subtle level and that is why we feel more relaxed, open, less stressed, more grounded etc.
Cultivating metta has effects on the heart chakra, for example. Seeing tilakkhana leads to a process of grounding, becoming less dreamy, an effect of sobering up. That we sober up will probably mean our lowest chakra’s are functioning more well. We become more grounded.
Practicing buddhism has effects on this subtle system. An expert can tell much better how this works.
Some buddhist schools have invented special purification practices based upon the understanding of these subtle processes and how they are influenced. Would the Buddha disapprove? I do not know for sure ofcourse, but why would he if they are conducive to the goal of reaching Nibbana?
If such practices would have the effect that a certain person does not stay a way from dasa akusala, then such a practise is useless too. But i think it can be helpfull, especially for people with blockages, trauma, intense experiences in youth which left big impression on the heart, etc. Maybe , for some person it can also be good to reach the goal of Nibbana to do some bodily work like yoga, or walking meditation or just sport.
A main part of practising buddhim, at least for a lot of persons, is dealing with blockages, with hindrances, obstacles and overcoming them in some way of the other.
Siebe