There are also accounts of mystical experiences being triggered by aesthetic rapture in completely untrained and unprepared individuals, for example by seeing a

There are also accounts of mystical experiences being triggered by aesthetic rapture in completely untrained and unprepared individuals, for example by seeing a beautiful view in nature or hearing a beautiful song. As you note there are many routes to the altered state of consciousness and sometimes people unwittingly stumble across shortcuts that do not require chemicals or intentional manipulation of the mental state.