It may be salvageable - but if most of the seams have frayed out that badly, I think I would just toss it and write it off as a learning experience.
Or else cut the pieces down and salvage what I could and resew them into something different and smaller.
One can wash cut strips - but I do it by soaking them in a basin of hot water - swishing them a bit with just a tiny dab of detergent - draining them - swishing them again in rinse water - if I have access to a washer, then I put them on 'spin' to get rid of the excess water - and then HANG the pieces to dry. The point is to avoid agitating the pieces.
And yes, there may be some distortion/shrinkage of the strips.