I posted a short video of ways to get rid of mistakes made in a piece of språng. In knitting you pull on the end and rip out your work, and in weaving you reverse what you did. With språng I have tried that, reversing what I've done twist by twist. Usually I lose track of what row each twist belongs to. To preserve that information and thereby save time and aggravation, I put in something to open the shed in a row above the mistake. Then I take out all the twists to that point but no further.