Another vote for the Mag-Float/razor combo.
Just for clarification in case you dont know what a Mag-Float is, its a magnetic cleaner. 2 pieces. One piece inside the tank, the other outside. Magnets hold them together on the glass. You simply slide the outside half around and the other half follows. Theres a scrubby surface (kinda like the scratchy half of velcro) to get the gunk off.
At first I was like "how well does this thing work?", turns out it works incredibly well, gets hard-to-reach-areas, and keeps your arms dry.