Both - Either

Hi,
If someone asked what's ok in "I wish I was/were rich", "was or were?", would you answer:

1. You can use both.
2. You can use either.
3. Both can be used.
4. Either can be used.

I'd say that all of the above versions are ok. Maybe "either" is better (since you always use one at a time, either "was" or "were"), but "both" is ok too in my opinion (and it is understood that you don't use both at the same time, but you can use both, alternatively). Am I right? Thanks

Oh my, I knew I should have thought of a better example!
The question is not about "was" and "were", but about "either" and "both" (and considering the fact that you can say "I wish I were..." or "I wish I was...")
So, let's change the example: "When people greet friends, do they say Hi or Hello?" Now, would you answer:

1. You can use both.
2. You can use either.
3. Both can be used.
4. Either can be used.

And my comments were:
I'd say that all of the above versions are ok. Maybe "either" is better (since you always use one at a time, either "was" or "were"), but "both" is ok too in my opinion (and it is understood that you don't use both at the same time, but you can use both, alternatively). Am I right? Thanks
Re-thanks

Well, there's enough context, I think.
I know the difference between "both" and "either", but sometimes I think both can be used in place of either, as long as it's not confusing. Imagine this question is asked here in this forum:

"I [have just seen/ just saw] your mother" - Which one?

You could answer "Either", "Either is ok", "Either can be used", "You can use either", etc.
Now I think you could also answer "Both", "Both are ok", "Both can be used", "You can use both"... Someone will say that it's not ok because you can't use both at the same time, you have to chose one and so you can choose "either". I think that would be being fussy since here there's no confusion. Everybody would understand that "You can use both" means "You can use both in those kinds of situation, but not together". On the other hand, if you said "You have to use both" then most people would understand you need both at the same time.

Now, is it just me that thinks so or am I right? Thank you in advance

Thank you.
It is interesting to notice that "both" wouldn't be ok logically, but the context tells you that it doesn't mean "both at the same time".