Just a thought... how about:
(1) Burying a double thickness "pill" into where you want your "line knot."
(2) Using Jeff's Method #2 to thread your line and secure your tubing.
(A) Double Thickness "Pill" using a small gauge wire snare:
DTPwWSa.jpg DTPwWSb.jpg DTPwWSc.jpg DTPwWSd.jpg DTPwWSe.jpg DTPwWSf.jpg DTPwWSg.jpg DTPwWSh.jpg
(B) Single Thickness "Pill" using a coffee straw fid:
(I'll have to post these pics seperate as I ran out of room.)