They work in the application they were meant to be used for. I have seen many situations where they were placed but were out of their normal design usage.
IF you fall under the IPC there will be no problem for this to be used (as long as you have 1 connecting vent, somewhere in the system, vented to outside air). UPC still seems to have problems allowing these. You will need to call your building department and talk about what code they use.
Good luck with you project.