crikey – I find it helps to imagine you are sitting round with a bunch of mates having a craic when posting on the internet. It generally means the conversation remains respectful of each other, rather than descending into ‘keyboard warrior’ mode.
The answer to ‘how much salt’ is ‘enough, if it gets into the wrong place’. Go get a handful of nails, and a shallow dish. Fill it up with some dishwash water, then put the nails in, then leave it and see what happens to the nails. Do the same with plain water, and bike detergent, if you want to see the difference.
It’s up to you whether you think this is cobblers or not. For me, it is much more sensible to use either plain water (which does a fine job most of the time), or a squirt of proper bike cleaner, that gets rinsed off quick. A £5 bottle of bike detergent every year or two isn’t going to break the bank.