The supposedly heat resistant concrete failed because it cracked and hot gasses forced their way in and under. If the rocket bidet I'd bet it will be for simila

The supposedly heat resistant concrete failed because it cracked and hot gasses forced their way in and under. If the rocket bidet I'd bet it will be for similar reasons, that the gas powering the water is wimpy compared to the rocket blast, and the bidet gets ripped apart because it could not keep the hot gasses out.