"mainly using" is correct and usable in written English.
You can use it when you are discussing an activity or process that is largely or primarily accomplished through a particular means. For example, "The project was completed mainly using online research."
Depth of tumor invasion was assessed mainly using ultrasonography (US).
I'm mainly using it for productivity suite stuff, desktop publishing, and watching DVDs.
Schaeffler has controversially accumulated control of over one-third of Continental's shares, mainly using derivatives.
But he identified himself as an artist, and in 1978 he began to paint, mainly using blue, because it was cheaper than other colors.
ABC News's main network competitors, CBS and NBC, are for the moment mainly using the Web to repackage their regular nightly news shows.
The Times claims that its reporter Patrick Foster identified Horton "by a process of deduction and detective work, mainly using information on the internet".
The drugs, officially known as anabolic-androgenic steroids, were first developed for medical use, with early abusers mainly using illicitly acquired pharmaceutical supplies.
But, of course, no it's about how to find other people's secret hideouts and flush them out, mainly using smoke bombs.
Mr. Martins noted that Mr. Eifman was mainly using Bach but would end with Tchaikovsky in his premiere for this segment.
The prospect of side-missions and exploration is handled mainly using a (once again) Crisis Core-like system of picking missions from savepoints.
The group typically transported two to four loads of six to 10 people a day mainly using rental cars, perhaps several hundred people in all, the authorities believe.
