Hello Sir Lal
I am not entierely convince by what you said.
Personnaly that don’t give me peace of mind because i still have kāma ragā. But i heard many monk and lays attain the Jhana with the sight of a dead body. The meditation center of Pa Auk in Burma use this kind of pratice. Of course they have wrong interpretations of the Dhamma. But they still had anariya Jhana.
In this sutta the Buddha invite Maha Mogallana to let his pratices and to lives like a regular bhikkhu. Maha Mogallana refuses and the Buddha asks why. He said he did for two reasons.
1. He was happy to living like that.
2. To encourage the futures generations to keeps this kind of pratices.
Lal i understand when you said that can be a ritual if we don’t have the right comprehension. But for me is really depend of the gati of each persons. Arahant Yasa was a lay before he becomes a bhikkhu and he was disgusted at the sight of the body of many young girls. This sight motives him to ordain. He quickly becomes arahant.
Maha Mogallana was in the perfect moment to stop this pratice he was Arahant already. No need for him to continue this but he keep it. His gati to pratice in the hard way and the benefice for the future generation. All persons is different.
In this Sutta the Buddha recommand to practice for reduces his desires that can be apply to all of the 13 Dhutaṅga.
You said that for a regular layman in a regular couple right? But what about a single layman who pratice the 8 precepts ??