Can we use "Not only, but too" instead of "Not only, but also,?

I am wondering about the use of "Not only, but too" instead of "Not only, but also.? For example:

The candidates campaigned not only in Perth but in Darwin too.

and is it formal to use it?


Idiomatically:

The candidates campaigned not only in Perth but also in Darwin.

The candidates campaigned not only in Perth but in Darwin, too.

Note the position of the adverbs.