Oh man, I hope this isnt the case!! I use GFS Lump (RO rebranded) and it is by FAR my favorite fuel. I have only found two rocks in the many, many bags that I have gone through - and never any fabric.
I recently bought some true RO Lump from Home Depot and I noticed the pieces are smaller than the bags from GFS. Looks like I will stick with GFS lump until I find some fabric.