Cut off the handle of an old detergent bottle, keeping the top and bottom openings intact.
Cut the bag and net bits to equal lengths.
Tie the bundle in the center with a long cord, 12"–18" leaving equal length tails, then zip-tie the bundle. It should now look like a tassel.
Attach the scrubbie to the handle. Take the 2 long tails of cord and pass them through the inside of the handle, then bring them back up along the outside of the handle to the opening with the scrubby bits, and tie them off. This should make a locking sort of tension, and create the kind of handle you can pass your hand through.