Upload & Sell: On
It's fairly simple to remove the back - peel up the grips and take out all the screws, lift the back and inch or so, disconnect the flexes. Putting some cleaner on the control wheel assembly from the inside usually works.
I use DeoxIt D. No idea what's in it, but given how effective it is I'm sure it's got all sorts of toxic, environmentally unfriendly chemicals. Stuff works though and it doesn't take very much. Deoxit Gold is, I believe, a gentler, more delicate formula so I don't bother with it.