It is cheap, but if you have an electric outlet near by (or can invest in a minor renovation), the high end ones are worth every pennies. Auto cleaning, misting the edge of the bowl to avoid stuff sticking, warming the seat and water, adjustable jet, and even auo closing seat and auto flushing, or being able to flush with a button on the wall. It's glorious.

If the girls want to give it a try they will almost certainly appreciate it. Everyone who has tried a bidet that I personally know has preferred it to just TP. Plus, I believe (from experience) that a bidet is essential if you're a mensurating girl or woman who uses sanitary pads.

But the best thing about a bidet attachment is one or more toilet users can choose to not use it and it's not any different from a bidet-less toilet. It doesn't get in the way or anything, so it's there if you want it but not any inconvenience if you don't. My husband didn't use ours for the first year we owned it but after he eventually gave it a try he's now a regular user.

Plus it's so ridiculously cheap ($40) that it's worth trying out.

It takes them a bit more getting used to be they benefit more, too. Make sure to get a model that can adjust the jet angle sufficiently.

Many bidets have mechanical valves and do not require electricity. Ones like this can be had for $20-30 on Amazon. We used one like this for many years, although when we bought our house we upgraded to electric.

Modern bidets heat the water and the seat, and nobody I know with one (including myself) doesn’t have TP next to the toilet too, you just need very little of it.

As someone with a bidet, there's no way in hell I'm sharing a butt towel. The bidet wash isn't completely effective. It's not the same as sharing a hand towel.