Connecting Gray waste to Black waste

I had a Colorado that had 2 gray tanks and 1 black with 2 dump valves. I previously used a wye. Then I decided to put a cap, with a hose fitting on, the one gray dump valve and connected directly to the valterra dumb elbow that had a hose fitting on it, too. But first, I had to punch out the plastic stopper on the elbow. I also had to cut off the male end of the hose and put on a female end. That way it could connect to both.

I was able to dump the one gray tank, with the hose. All I had to carry was a dedicated "gray" hose, instead of another "stinky-slinkly.