It depends, is it cotton chenille or is it a man-made fiber? The cotton chenille will work very well in garter stitch, but sometimes the chenille with acrylics and other things are rather slippery and you can have worming with garter stitch.
If it's cotton chenille, I love making washcloths, but a blanket in garter stitch would be lovely too.
"I have loved the stars too fondly to be fearful of the night"
See what I'm knitting over at my blog: Knit Luck