Sounds very similar to the "Mo-Flo" by Snorkel Bob ... http://www.snorkelbob.com/cgi-local/SoftCart.exe/online-store/scstore/moflo.htm?L+scstore+dxjj9668ff70f770+1179514072
On the one I saw in their shop the tube is about 2x normal size so there is no change in breathing resistance, but I have not tried it yet to see how clearing works.
On the one I saw in their shop the tube is about 2x normal size so there is no change in breathing resistance, but I have not tried it yet to see how clearing works.