I just received my order of Ekowool from Stormy's today and got to work on building a coil for my Chalice. I always liked silica as a wick, but after all the info on it's potentially hazardous long term effects I figured it was worth giving the supposedly safer and ecologically friendlier Ekowool a shot. There's more info on other ECF threads and the Ekowool official website, and based on that info I decided to get the 2mm strands and gave it one loop. I used 32 gauge Kanthal A1 wire, about 5 wraps for a 2.1-ish ohm resistance.
Just wanted to share with fellow REOnauts, even those that don't use silica for flavor or health reasons, that this stuff so far has exceeded my expectations as far as wicking material for RBAs. It wicks amazingly well, better than cotton or regular silica ever did for me, and it retains a remarkable amount of liquid between squonks. The flavor: some of the cleanest flavor I have experienced, even after having dry-fired the coil to check for hot spots.
The pic above (right) shows the coil with one squonks worth saturation after taking about five pulls with tons of vapor; it still looks very saturated, because it is very saturated. I though the fraying (shown on left pic) would be a problem when installing since I like leaving a least one longer strand to soak up residual juice. I ended up cutting it flush at the ends since it turned out the fraying creates like a super-mop of smaller wick fingers that sucks up any liquid in its path.
I highly recommend this stuff for RBAs on REOs. I personally feel it has improved what had already been the best vaping set-up I had tried. I can't say for sure whether it's safer than regular silica, but I can surely comment on its superior performance.