No laughing here either.
We also bring our own. One of our suitcases we take is designated as CC suitcase. It only contains snorkel gear and sand toys. When we get on the ship, we roll it under the bed until CC day. then we roll it off the ship and to the island. end of day, throw the stuff back in the suitcase and roll it back to the ship and back under the bed until the last night when it comes out to go to the porter. Works Great!
I know that they clean the snorkel gear they rent, but I still have issues with the mouthpieces, that I have no idea where they have been, going in my mouth. . . .
They have no issue with you using your own gear, as long as you wear a snorkel vest, which they provide at no cost at any life guard station.
The last time my youngest wanted to go snorkeling. She lasted maybe 2 mins. Glad I didn't spend all that money on renting gear for 2 mins. (She loves using the fins in the pool at home)