I put the skimmer socks on the skimmer's basket and then pour about a pound into each skimmer. No more then a half full basket so there is plenty of water going through the skimmer. The pump is running 24 hrs. right now so the CYA is gone by morning.
No need to worry about backwashing the stuff out by mistake.

I use those skimmer socks all season. Really eliminates backwashing my sand filter. Does a great job on the tree pollen which require a daily cleaning on the socks. They have been so full of pollen, the flow would actually slow down.

Joe