No, use W so sheen procs for the next auto-attack. Q applies on hit effects such as sheen. Don't forget W slows oponent attack speed so it's important to do that first if you are going againest another AD carry.

Well this is an alright guide but using your Q won't power up your W as
1. the Q applies on-hit effects
2. the Sheen's proc only works on auto-attacks.
I might be wrong, but I think you were saying that the Sheen's proc would power up the W.