I use my twin needle for decorative type stitching. I may be wrong but if it can zig-zag it probably can use a twin needle. I use my two threads on my two thread holders, thread each thread through the tension disks, an then thread each color through the eye of one of the needles. You get a really nice effect. I also use a triple needle for this sort of thing as well. You can do really interesting stuff with a wing needle as well. If you're going to play around, might as well try everything you can think of.
Make sure you walk your machine through the stitching pattern before taking off. You don't want to try stitching something wider than your machine allows!