We just came in to CDG on United and tried to use the lounges. Indeed, turned away at the Star Alliance lounge as a Gold. Did not think to try my Priority Pass there. Then turned away at the iCare lounge down the hall.
Interestingly, used the restroom in the hall between the lounges and there was a shower in it. So, if you need a shower, just go on up with your luggage. There were no signs or other indications that these were owned by anyone. I did not see towels, however. So bring a small one.