Using liquid enamels can work. You can dip or spray light layers on.
If you have access to a spraying booth, you can get the turn table to
turn the cylinder while you spray. Dipping can give you an uneven
build up, if you don't have something which really holds the cylinder
well without getting in the way.
The trick is to do light layers and thoroughly dry each layer in
between. The layers must be light or you get slumping. Of course if
they're too light, you get spots. While I haven't tried it yet, I was
thinking that it might be useful to sift a coat on after using the
liquid, much like you do with a bead.
If you are going to make your own liquid enamel, which is cheaper and
lasts longer (the already madeup kind dries up moderately quickly),
look at the article on the Glass on Metal web site. It is a pain
getting the enamel to the right consistency. If this is a one time
shot, you might go with the prepared.
Depending on the height of the the kiln and the height of the
cylinder, you can use a bolt threaded throught a mesh to hold the
cylinder. The bolt needs to be at least half the height of the
cylinder to keep the thing upright. The bolt worked well for me, I
got more slumping with a rod.
However, If you can do the bit with turning the cylinder while in
the kiln, it would be great. I still haven't figured out what a
spider is, or worked up the nerve to punch a glory hole in my kiln.
Maybe a spring like in a wind up toy would work in the kiln?