Morning Strathavon, Yep, rubber strips are a doddle to remove. When out using a very narrow wire channel brush clean up the rusted screw heads, they clean remarkably easily and you'll wonder how so much rusting has such little effect on them!
On refit I use red rubber grease for 2" on top of the cleaned heads and silicone grease on the rest of the channel as if you use a grease product on the whole channel the rubber tends to pop out. The silicone will wash out and you only really need it to ease the fitting of the rubber. When all back together run ACF-50 under all the channel between it and the wing. Let it sit overnight then wipe away residue in the morning. As Richard said, that's where the corrosion from water ingress originates. Most things on a Mog require finding the cause and rectifying it rather than treating the effect it caused.