Making scrappies - can I use some super wash?

I've lots of bits and pieces of wool and was thinking of making some scrappy longies. Can I include some super wash wool? Would it be best to limit it to the legs, or doesn't it matter?
Also is there a minimum size each scrap should ideally be?

I've never made any but would guess superwash would be fine for the legs

i used sw on a pair of dungrees i did and kept it to the bib and legs and it worked fine.