Egyptian multi-hose hookahs usually lack a purge valve. To smoke one properly , one person must plug off the end of their hose while the other smokes.... or you take the other hose out and put in a rubber stopper in the second hose port for single person smoking.
There is a way to make a small device which goes in the second connection that converts it inot a purge valve. It is made of parts found at the hardware store and a BB or an airsoft pellet.
Heres a pic of one I have made in the past.
It is made using a rubber stopper with a hole drilled in it.... The second part is a Hose-barb adapter, you place a BB or airsoft pellet in it... and then the third is a screw on cap for the adapter.... you drill a small hole on the end of it to let the air pass.