Well, I stumbled upon this thread while trying to figure out way way to lower the amount of foam produced by my new kegerator and thought, amazing! I placed an order for some of these devices and waited until the weekend to install.
Since I'm not using corny kegs, the hose is crimped to the end nut that goes to the sankey so there was no way I was going to be able to slip this in there. I then went to the faucet end of things and was able to remove the hose there since it's fitting was barbed. After all of that, the interior diameter of the hose is too small for one of these!
Bummer... Even at 5-6PSI I get tons of foam, what gives? I've purged the keg and re-filled, and use a very nice dual-regular setup...