For a student that has no practice whatsoever in their body (asana) and has no background in yama and niyama (and how to apply same in their living) it may be best to begin with gentle practice. Further, it is the context we are trying to alter not the plumbing, though in some instances a mild cleanse is completely appropriate. In other words, to clean the pipes but not address the underlying inability or unwillingness to deal with the cause(s) will only be a band-aid not a healing.
Restorative asana (completely supported) along with gentle pranayama (viloma I) is where I’d begin as this will introduce the practice, set the stage for alignment, and foster a parasympathetic state in the central nervous system.
Diet is a huge matter and consists not only of what to avoid but what to eat. Since the person you mention has opted for antibiotics it would be hyper-critical to be taking a quality acidophilus source on a daily basis. Most people who’ve cycled through ABs wind up with overgrowth of candida and therefore the diet would lean toward removal of sugars and certain fermented items like soy and vinegar. In addition the stomach’s nature is acidic. This is the way it functions properly. So acid should not be removed from the stomach.
I personally would not be using cleansing methodologies from the HYP for a beginner.