How to orient elbow adapter correctly?

[fowlerboi]

install a pipe interrupter between the valve control and the hose

If you're on the mains then you're stuffed

 

[Basher]

Provided it isn't left submerged in the toilet pan for a prolonged amount of time

If I was on the same mains water supply near you, I wouldn't want you to EVER submerge the shower head in the toilet pan!

 

[JStracks]

If I was on the same mains water supply near you, I wouldn't want you to EVER submerge the shower head in the toilet pan!

Certainly not planning on it!

 

[Ric2013]

I suppose the risk is largely if the hose is submerged (or in use) at the time a drop in mains pressure occurs. You may use it very carefully, but can you guarantee for others and potential future purchasers? You'll find people can be surprisingly stupid about these things.

If you can't fit a separate bidet, you can buy a care home type bidet toilet if space is an issue. They incorporate a break tank and so they comply. Or you put a tank in the loft and pump off it, plus another hot water cylinder if you want hot water too.

I suppose the problem is if enough people take the attitude that they'll just break the rules when it suits them, eventually we'll end up with an Australian-style system where nobody except a licenced plumber (which will be expensive) can touch anything, or an Italian-style system where everyone seems to ignore the rules (if they exist).

I think bidets are a great idea, but don't have one in my house for the same reasons you are finding installing a compliant system so hard. Rules aside, make your own mind up - I've said my piece.