Okay I am outing myself - I havent been around for a while on the forum - but this thread reeled me in quicker then one of those long lines in an earlier photo.
I've mentioned before that I have been working as a threader for over 25 years - and at one stage was doing some work for Paspaley (not name dropping - just background).
Theres really no "Magical Trick" - but its a technique that those who know it hold very close to their heart.
There's no "Special" thread needed - it could be Silk - but I dont recommend it - or you can use any other beading thread of your choice. My personal favourite is an Australian made thread by Kaygee products based in Western Australia.
Theres a lot of mystery surrounding threading and knotting - I'm always amused at all the gizmos and special tools etc that appear and re-appear as must have's. Theres no need to overcomplicate the process - the only tool you need is a pair of tweezers - yes there is the hand only method - but for me tweezers give a cleaner result - also awls pins and nails arent needed if you use the tweezers appropriately.
So the mystery continues .....

I cant say more - as the guild of invisible knotters would string me up.