I use 2 mm silica for the main wick, although 3 mm also works well. 5/4 wrap of 32 puts me in the ohm range I like, and then one full strand of cotton yarn for the flavor wick.
Doing that, I can still dry burn when needed, and just replace the flavor wick.
If you use too little wick - of any type - it will probably leak down the center pin. Too much, and it may not wick well, although that's less of a problem with BCC than with top
coils.
You can lay the wick over a long needle and wrap the kanthal there, or if you want to wrap the kanthal say on a 4-40 machine screw, you can wrap the end of the wick with teflon "plumber's tape" to make it easier to
thread through your new coil. It comes off easily.