It is gym ettiquette to clear plates off of machines when you are done, and to put dumbbells back when you are done with them ...
But, as you have seen, not everyone plays by the rules.
I am working in a new gym now, and am having to break the sloppy habits of the members here. Alot of them just leave stuff on the machines and leave dumbbells laying around.
Does your gym have staff on the floor? It is part of their job description (I am sure) to clear the floor of dumbbells, for safety reasons if nothing else.
Also, I am always ready to help anyone who needs help unloading plates from machines. Your gym staff is probably the same way -- sympathetic to the situation since it is usually lazy members (mostly male) that are the culprits. It's no problem to ask.
I make myself available on the floor when I am in betwen clients, and I also clear machines that are overloaded. AND if I see someone leave a machine that is loaded up, I go up to them and ask if they are finished. If they say "yes", then I offer to help them unload the machine. --
"You finished there?"
"Uh, yeah" "Cool. I'll help you unload it."
If it is dumbbells (and it always seems to be the 120 pounders that are left around
), and I see someone walk away from them, I rack them, but them I will walk up and ask the offender to rack them himself next time.
Usually when I am floating around, people clean up after themselves. It's when I am not looking that it all goes to pot.
Oh, and we have signs everywhere too. The burden is on the staff to keep a safe exercise floor, but "good members" who know the ettiuette are always a nice thing.