I use Maxi Lock on all four cones - if I use Woolly Nylon I only put it on the lower two loopers. I think you can use it on all four if you want though. It's hard to thread through the needles and small holes - so paint the ends with some nail polish and roll them until hard and dry - then they'll thread easily.
I use Maxi Lock for clothes and diapers and everything I sew.
HTH!
I use Maxi Lock for clothes and diapers and everything I sew.

HTH!