I've always washed my mf's before first use.
this is a little off topic but i need to rant. I just got my order from pakshak a couple days ago so i wash them, but i leave to go to the store for 30 mins. when i come back home i find my towels in the dryer on high heat!:scared :angry My roomate thought he would help me out and throw the brand new mf towels in the dryer. I was sooo mad, but it turned out the towles were not completely ruined which was a shock to me. *i DO NOT reccomend anyone dry their mf's on high heat* i believe i got lucky.
end of rant..
i guess that is a lesson i learned abbout the care for mf, never leave your house in the middle of a job!