Can't help you with the mouth, per se, but on a day like yesterday I stayed in the river. My wife and I came out of the shipping channel made the turn to head east into Erie and said "no thanks." I made a u-turn and headed back for easier fishing. I pulled a nice mixed bag of green and brown bass in one 50yd stretch, back and forth in 1.5hrs.
Not trying to be too vague but targeting the rip-rap walls on the outside of the channel can get you some fish. Cruise the walls and look for boulders, they are quite often next to a drop and some weeds, work those "holes". You will also find spots where the base of the wall has a little point with a ledge, hit that. There are boulders and weed patches all over the many flats. Got a Canadian license? Fish their islands, sea walls, and flats.
Sorry it's not exactly what you were looking for but I hope it helps another day get you some fish when it all else fails.
Forgot something, sorry: I used to do "ok" (I guess) cruising/drifting on the flats off of Pt Mouillee. Just remember to check your depth since they move...