What you are describing is called inside picking, a specific form of alternate picking.
Paul Davids talks about it in this video for the Snow Hey Oh riff. It requires more precision and nuance than regular alternate picking but in theory you can alternate pick faster using this technique.
However, I think it would be best for someone learning guitar to seperate these techniques. This is not a substitute for regular alternate picking, it should only be used when necessary due to the increased precision. Regular alternate picking is more useful to get in your muscle memory because you can skip strings while using it, this technique can only be done with two adjacent strings and most of the time will be unneccessary - stick to normal alternate picking.
Hope I answered your question
