I have a J&M panhard bar and I put grease on the nuts where you adjust it to keep the area from rusting, but it seems that all I've done is make it so the nuts keep coming loose.
I don't have a wrench large enough for the nuts so I've been using chanel-lock pliers to tighten the nuts, but shortly after that I find them loose

I'm thinking of washing off the grease with brake cleaner and tightening the nuts back up one more time ...

Any thoughts/recommendations ?

 

My suggestion, buy a large enough wrench and be done with it. Use the right tool for the job or expect failure.

 

I did the same thing and it loosened up. I retightened and put locktite on. I bought a set if wrenches just for the panhard bar and it goes up to 26mm come to find out its even bigger. If mine loosens again I'm going to harbor freight and buying the one wrench that will fit.

 

From what I can find I think the size is 1 1/8" ... there's a fairly local Harbor Freight here too, but there's an Autozone VERY close-by

 

Where are the Koni's?
All the info I have read says to use loctite.

 

The bar was installed and pic taken before the Konis and Steeda springs

 

And I'm done with this, at least for now.

I went out, sprayed the hell out of it with brake cleaner, backed off the left nut (the one that kept coming loose), sprayed the threads, went to the store, got a multi-pack of wrenches to 1 1/8" and some red thread locker, got back to the car, applied the red, then used the 1 1/8" wrench to tighten the nut as much as I could with the leverage I had.
The packaging said the threadlocker takes 20-60 minutes to set, 24 hrs to completely cure.
Not going anywhere for at least 2 hours.
While I was outside playing with the car I went ahead and squirted some grease into the LCA grease fittings since I was starting to hear a bit of squeaking from the rear going over speed bumps.

So we'll see.

Current look under there:

 

good show loctite FTW

 

One other thing to check torque on while you're under there... The u-channel bar above the panhard. I changed mufflers last night and pulled that bar down so the left muffler pipe and clamp would more easily clear, giving me extra room to pull the muffler forward and off the front hanger. I found the bolts on that bar to have very little torque on them. My '14 only has 600 miles on it. If anyone gets a chance, torque-check 'em.