There are various C02 traps like that ranging from diy to propane setups. The real question is, will it matter? I dare say in some places you'd have to deploy like 50 of those and it still won't make a dent. But it is cheap and, if you're real desparate, once it stopps bubbling you have a mildly alcoholic mosquito cocktail. Bottoms up!
On the river, I can abandon who I am and what I've done. However brief it lasts, while on the river I am nothing important and everything insignificant. I am flotsam, and happy to be so.