The spider or cob web shooter gun is essentially a hot glue gun with a stream of air to catch the hot glue strands and stretch them out and spray them onto another object. If you have used a hot glue gun you know that when a gun is very hot the glue is very liquid which is what is required for a good gun. The hotter and more powerful the heater in a gun the more you can shoot without waiting for the gun to re-heat. Since you are blowing a very hot liquid glue there is a good chance the hot glue can get kicked back onto the user. The second video mentions use of wearing cotton gloves which may help. I have found that using any hot glue gun on very cold nights outside does NOT work well. The biggest issue is with the gun not being able to keep up. Indoors or on a sunny warm day really helps the glue. If too cold the glue will also cool too fast once it leaves the gun and not stretch well. Also on a very cold day the air is also cold blowing the glue.
We have sell the colored glue sticks in florescent colors and look great under a black light. We do caution on the yellow sticks that the glue is harder to spray. The yellow colored wax which colors the glue stick is harder than other colors or clear and requires more heat to melt. Yellow is slower to apply and can glob easier when not heated hot enough. This is due to the yellow color being a dull color without a higher concentration of the colorant which does not melt as well. I recommend all the other colors above yellow.
If your on a budget here is a great video from youtube where the author shows you how to do the same effect without the expensive web shooter. I have yet to try this one out myself, the air outlet is much bigger than commercial guns and may result in a shorter shooting distance. The commercial guns can shoot webs very high on on objects much further away which may be desirable in a large or ourdoor setting. I shoot on tree limbs and up high which would not work with this scenario. Excellent demonstration though.