It needs the air gap and won't work right if you do what you're thinking of doing.

Perhaps the standpipe and/or trap underneath it could be partially plugged up. I think that's a fairly common problem. Try pushing a garden hose down as far as you can and then turn it on to blast the water down the drain in short powerful bursts.

 

Try duct tape, not silicone. Leave a little air space.

 

Used some duct tape (good ol duct tape!) - with some zip ties around the 'corners' of the circle. Did the trick!

I can still hear air suctioning into the pipe too - so it's not air tight.

 

Amazon has pipe brush.

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For mist, a small towel? Also check the end of the discharge hook for damage/rough surface. Never had a mist problem there.

 

The connection of the drain hose to the drain pipe must leak air freely

If all the air you hear came from the washing machine mixed with the drain water then that is not good enough.