We have all done it. Bought an expensive yarn for a special project only to find it almost impossible to unravel when you find your stitch count wrong or that you did row 3 twice...etc.
What to do?
You can salvage what you can and throw the rest away, kicking yourself the entire time for buying that yarn in the first place...
Or you can try this method.
As you can see, I have a skein of Patons Lacette yarn pictured. It is a lovely soft yarn that works up easily, but almost impossible to frog!
I've worked with other yarns like this, with a softness that is more like a cloud of fuzz, fuzz that gets caught over and under your stitches, knotting into an impossible mess when you pull to unravel it.
Here is what I do:
I began by lightly pulling at the yarn to release the stitches-mistake. As soon as I fill resistance I stop pulling. I open my scissors so I have one point and gently insert it between the problem (in this case the fuzz) and last stitch or chain. This frees the yarn so that you can go back to gently unraveling your work.
Above are several photos illustrating the process.
In this way I was able to frog the entire piece, saving almost a full skein of yarn.
This also works well with eyelash or fun fur types of yarns.