The major difference being that the UK-approved on is a ceramic heater: a resistive wire suspended in ceramic, encased in a grounded metal sheath (for transfer

The major difference being that the UK-approved on is a ceramic heater: a resistive wire suspended in ceramic, encased in a grounded metal sheath (for transfer of heat). Regulations demand fixed cabling, of appropriate size, all on a quick-acting 30mA-leak RCBO at the consumer unit. Ignoring regs is a good way to lose your accreditation, get sued into oblivion so most electricians follow them to the letter and beyond. Paperwork to that fact is required for the installation. If the wire touched the metal, or water got into the element and bridged the circuit to earth, the breaker would cut out immediately. The suicide shower relies on the exposed resistive heater having a lower resistance than the water, and then a functional earth-leakage breaking device. In perfect conditions, they're probably Safe Enough™, but there are so many failure modes. Earth failure (corrosion? never installed? fast enough?), dodgy water chemistry, exposed cabling, an exposed join because the included terminations are only ~15cm. Often installed in countries without rigorous electrical safety standards. Just a bad idea.