FWIW, fixing is recommended by Haist and other authors too I'm sure. It shouldn't matter in theory since you've removed the negative silver image and developed the positive silver image, leaving no substantial amount of silver-halide.
But, there are always a small number of silver-halide grains that are orders of magnitude less sensitive (if at all) to light, and thus don't develop. Haist recommends fixing, and the hardening aspect is an added (if not needed) bonus.
Got it. Thanks! This looks like the easiest way to make positive b/w. Thank you guys for posting this. Are there any downsides for using this method to make enlarged negatives for alt processes? Also, does this method require exposure adjustment?
Personaly I use traditional selenium tone (1:3) after fix and wash. It works great. I looked at a fogging dev, but it really isn't that big of a deal for me. It also allows me to bail earlier when things don't work out.