Hello: I have several very nice and antique toilet bowls which I want to turn them into fish bowls and I need to find a UNIVERSAL plug that is flexible enough to fit all of the drain openings to plug-up the drain hole of these toilet bowls. When I need to change the water in the bowls, all I have to do is to remove the fish, unplug the plugs and flash the dirty water away. Where can I find these plugs and if not, where can I have some made? Thank you very much.