I did a search for "slow drains" but didn't find anything specific to laundry tubs (or trays).
Mine has slowed to the point that the output of the washer is filling the thing almost to the point of overflowing. It then takes hours for the water to drain out of the tubs. (This is a dual tub, so what the washer dumps into the left side backs up into the right one, filling it also).
I've tried using a plunger alone, then I tried the baking soda plus vinegar method that worked so well for my bathroom sink. No dice. I don't want to use anything caustic like Drano or Liquid Plumber because (a) some of the plumbing is plastic and (b) the other parts are pretty old. And the tub drains are small...only about an inch and a quarter in diameter, so I don't see how I could get a snake down there.
Before I call the plumber, any suggestions?
P.S. Yes, I know, I should have some kind of strainer or filter over the washer hose to prevent the lint from plugging up the drain.