i make them with foax suede or leather, and i have a special
spray for fabric that is fire resistant. Downside being you cant
wash them very often, BUT I sell the spray with each pair of
pants. And the string I use is a very thing light twine, used
for beading, but fishing wire works all the same, and for the
firewand I use kevlar string.

it doesn't have to be a certain
weight really, its all about balance, object manipulation, and
the placement of the string must me about a half inch off center.
the part of the wand with less length being the top.