I question the whole concept of electrocution by dropping a mains connected item into the tub.
Electricity takes the route of least resistance. If the hot and neutral wires are in the water, the current will flow directly between them. Likely tripping the breaker. Why would the current choose to flow through the water, to a human body of much higher resistance and then back to the other wire?
To actually happen, the water would have to only contact the live wire, then go through the water to a place of lower potential. Again, is a human body the best path to the lower potential, which would be some point connected to ground or neutral.
Worst case scenario is being in a tub full of water that actually is connected to ground via plumbing. Reaching out and grabbing an electrical device. If your wet hand actually somehow provides a path, then you are now the best conductor between the hot wire and the grounded bath water.
But. My bathtub is not grounded. All connections to it are plastic. Many are as such these days. Better protection against murder attempts. Better just cut the brake lines honey.
Electricty takes all routes simultaneously in inverse proportion to their resistance.
Most significantly for safety, the potentially fatal dose of electricity is vastly smaller than e.g.20A at 120V. Your body csn be the 8th (or 20th) least resistive path and still absorb a far more than lethal dose.
For damned surevtge adventnofbplasticctibs and pmatic plumbing and portable appliances with plastic cases has been a huge boon to electrical safety even before we add GFCIs, quick acting magnetic circuit breakers, polarized plugs, dedicated ground wires, etc.
I just want to take a moment to say that something that’s always bugged me is the idiom “water and electricity don’t mix”. They mix just fine, what people should be saying is “you shouldn’t mix water and electricity”.
(and I’m well aware that pure/clean water won’t conduct electricity well, but that’s not the point)
If it truly is electrically floating, there may not be a shock at all. It would be sort of like when birds perch on a high voltage power line. They are connected to the line, possibly at thousands of volts but not to ground. There is no path, so current does not flow.
Very large birds, like eagles can come in contact with two wires at different voltages. They get cooked.
Once in awhile squirrels or such jump between the wire and the pole or suspension insulators. If they goof & bridge the gap the results are instant. The YouTubes are sad and funny at the same time.
In short, while you might conceivably manage to kill someone this way, it’s clumsy, overly complicated and unreliable. Like most murder mystery plot devices.
Fellow I know told the story of someone hunting moose up north. They’d climbed the transmission tower to get a good view looking for moose. They were smart enough not to touch anything close to the actual wires or insulators. However, those wires are hundreds of thousands of volts, and he got close enough to get an arc to the metal tower. On the plus side, he tripped the breaker back at the generating station, so his buddy could get him down safely. On the plusser side, apparently the Hydro company people were doing some maintenance on the line somewhere, so the automatic reset was not enabled, or there would be two fried hunters. And amazingly enough, a few days in the hospital and he was out again, to get plenty of razzing from his buddies - and no moose.
The main reason we don’t try to run residential electrical systems isolated from ground is that mother nature tends to randomly insert ground connections into your system. Better to have a dedicated ground than a random grounding system.
Your bathtub may very well be grounded (at least well enough to cause a shock hazard) if the water is running or if the water is draining. The water itself provides the ground path.
One such suicidal squirrel managed to short out a main transformer in the substation closest to my house. He managed to take out power for about 5,000 people.
