Hi Waldine
I generally boil water and pop the plastic cords into it for a few seconds at a time - try not to get the needled wet if they are bamboo - if there metal it doesn't matter so much, but you do need to be able to hoist them out of the water and pull (not hard ) to straighten , pop them back in again and just repeat the process till the coiling has almost gone. Dry them off and you're ready to go.
Gracie
p.s. welcome
I generally boil water and pop the plastic cords into it for a few seconds at a time - try not to get the needled wet if they are bamboo - if there metal it doesn't matter so much, but you do need to be able to hoist them out of the water and pull (not hard ) to straighten , pop them back in again and just repeat the process till the coiling has almost gone. Dry them off and you're ready to go.
Gracie
p.s. welcome