sunnah method of ghusal

Explaining to someone how to perform ghusal

Q: Suppose a boy has to do ghusl for janabah and I need to inform him how to do it. Ususally people tell them the obligatory acts in ghusl which are three. But I think that this is not sufficient because there are many precautions in ghusl which should be taken and known so that one has a valid ghusl.

So when I want to inform someone about fard ghusl and I just said to them about the obligatory acts and they follow those their whole life but are unaware of the precautions then their ghusl would be invalid their whole life.

And how can I tell them all the precautions. And if I tell them also then I fear I will remember another precaution after some time which I forget to tell them and if they did ghusl and then how can I tell them the forgotten precaution and tell them to repeat the ghusl? And some things which prevent water from reaching the skin such as wax or sticker etc. That things also I need to tell them and after that I remember some more things which prevent water from reaching the skin amd if I tell them thses many things for a ghusl they will think that I am too deep in religion and I don't know if they will listen or not.

1. What do I do?

Precautions means the things which most people forget to do in ghusl. There are 20 for men and 6 for women, I will mention one of them "The joint between the chin and the throat will not be washed unless you lift your head upwards." Like these, there are many.

2. While getting up from sleep we have bad yellow particle on teeth before brushing, must those particles be removed before doing fard ghusl or just gargling in sufficient?

3. What about the food stuck between the teeth?

4. What about the tongue, should the tongue be cleaned with a tongue cleaner before fard ghusl because there will be some particles spread on the tongue which can only be removed by a tongue cleaner?

Ghusal

Q: If I take a bath and clean my nose and mouth in a wudhu way, would it be considered to be wudhu? If so then shall the water reach all parts of my body while bathing? What about ears?