It is of course, possible to buy commercial tools for combing hot glass. But with a little ingenuity, you can make your own for a small amount of money and some effort.
My raking tool is a metre long round stainless steel rod, 8mm in diameter. I sharpened it on a grinder for metal rather than my glass grinder. Then I bent a right angle to give me 75mm "hook". The handle is a piece of broom handle. I drilled an 8mm hole in the wood and hammered it on.
A longer metal and shorter wooden handle works better than the one I made with a long wooden handle, as there is no wood near enough the heat to burn. If you do have a long handle, soak it in water to keep it from burning.
It is possible to make a rake using mild steel rod, but it is more likely to spall and drop flakes into the glass. Both metals need to be kept cool. Rest the rake in a bucket of water before the first pass at combing. As the glass stiffens and you need to wait for the glass to come back to a combing temperature, put he rake back into water to cool it. If you try to comb with a hot rake, it will stick to the glass.
It is important to have a handle made of an insulating material to avoid any possible electrical shocks. It also makes for a more comfortable handle that does not heat up.
Safety gear is required to protect eyes and clothing from the heat. It is not possible to have the kiln open at around 900C without it. This is the face, hand and arm protection I use. The coated visor protects your eyes against the infrared radiation from the kiln. The gloves can be the aluminised silver colour ones or the kevlar ones. The alminised ones are easier to manipulate things with. The arm protectors are aluminised too. They are easy to put on and give additional safety to the body.