A lot of creativity is shown regarding bridges on the CB instruments I've seen. The quintessential eye bolt seems to show up a lot, dog bones, ball point pens, bottle caps... all kinds of cool stuff. These obviously works great for plugged in CBs, [& for aesthetic "funk factor"] but what about acoustically?
In most non amplified instruments some general rules of thumb I've observed:
1. Most are made of pretty dense material like bone, ebony, rosewood, maple, corian etc.
2. sometimes the body of the bridge is made with dense material like, ebony, rosewood or maple and capped with even harder materials like for banjos ebony atop maple and guitars bone on ebony.
3. Softer materials tend to absorb highs and denser materials accentuate them. I've used this to advantage on instruments like hammered dulcimers by capping the bridges with Delrin [a sort of self lubricating synthetic - I think it's generic name is acytal] this not only helped reduce friction to make tuning easier - it filtered out some of the high frequencies that HDs often have too much of anyway.
One of the ways you lower the volume of traditional stringed instruments is by using a "mute." [And in spite of what one of my T-shirts says a banjo mute is NOT a 9 lb sledge hammer...;~) ]
These are weighted clips that fasten to the bridge of say a fiddle or a banjo. This is helpful if we're trying to balance their volume with other acoustic instruments. But this also tells us that all else being equal, if you merely add weight to a bridge is reduces it's ability to vibrate freely and pass that vibration on to the sound board, and so the instrument gets quieter.
With all that said, I'm guessing large eye bolts work against us if we're trying for optimum sound unplugged. An easy experiment someone might want to try is make a few bridges of different materials, but all the same height, and test them on the same instrument. If you have a cohort who's got the patience a blind listening test might be even a little bit scientific. Any takers? Recording the results and comparing that way might be cool too, but keeping all variables the same can be tricky.
I was using an oak bridge/saddle and it worked fine, now i have switched to a wood bridge(mahogany I think) and a small brass rod saddle. The sound is still good, to my ears not much different. Reason for change is the new bridge houses a piezo. I was worried the new bridge would dampen some beacause it is larger and covers more of the soundboard , but it did not effect it.
A domino works great. They're extremely cheap too...I bought 20 for like $2 at Wally World. Cut them into 1/4" strips and slot them for strings, not too deep though, they seem to play better with smaller slots. They won't scratch your box and are pretty easily adjustable. One word of caution, they smell God-awful if you burn them with a dremel tool cutting bit so my best advice is to wear a gas mask. They also shed like corian when cut and a regular dust mask won't rid the smell.