A Dora gun kit is on the list to build and want it to appear like it's firing. The following was the first video I've stumbled across that really pulled it off well in my opinion in a relatively simple and cheap way.
https://www.youtube.com/watch?v=ATKUT4eNL6E
But, being lazy, cheap, and always stubborn, further simplification and cheapification were required. Here's the result. This is the first attempt and has had no rework/clean up.
https://macfixx.smugmug.com/Impactful-statement/
3 "regular" LED's stolen from a string of Christmas lights were brush painted with thinned bright orange. Various sizes/chunks of fiber optics were applied to one LED with tape. A crude wire "cage" was made with a chunk of lichen stuffed in the middle of it. I tried wadding up clear plastic cling wrap but too much light escaped IMO. The smoke is fake spider web material. I find it much easier to work with than cotton and a large bag only costs $1. (even cheaper after Halloween).
Once all in place, cheap pump liquid hairspray was doused over the whole thing. Then thinned out red, black, and brown acrylics were airbrushed on. The fragment trails received a heavier coat of red.
Fast, cheap, simple. Less than an hour total to make. The 2 AA batteries were the biggest cost.
Nano LED's (like those on a wire string often stuffed inside wine bottles and jars) will be tried the next go around to scale the whole thing down. "Hearing aid" sized batteries should last for quite a while on those and be easier to conceal.
Mac