What I have always encouraged my lockerroom mates to do is post the article in the lockeroom and teammates can proof-read it for you. I've done it before and as long as there's at least one member who is willing to do it, it works out great!
My suggestion is that the team creates a "Proof-read Thread". This way, you'll be able to see the corrections, learn a little more, and not have to worry about the grammar so much as part of the grade.