I am desperately trying to get all of this ugly dark blue latex paint off the walls of one of my bedrooms. Nothing works at getting it off. We've tried the wire brush. The scraper. Even spraying it down with mean geeen to try and loosen it. What can I use to get this off the wall so I can repaint?
Painter here. If paint doesn't want to leave the surface, I generally don't ask it to. I just paint over it.
Deep colors are a PiTA to paint over if your ultimate destination is an off-white (like most all housepaint). The key is to use a primer with high opacity and hit it with several coats until it is covered and the surface looks uniform. Primer is cheaper than paint and is better suited to coverup surfaces of differing colors and textures.
The biggest problem you get laying it down uniform is that the roller doesn't put it down evenly. That will be disturbingly apparent on the first coat, but don't give up. The second coat will be much better, as the color will only punch through where both coats happen to be thin. Coat #3 will be vastly better still. Somewhere around 3 or 4 you will reach "good enough".
There is a lot of ways you can try. It is better to use some powered tools.
An oscillating multi-tool with scraper blade. That's usually much more powerful than a hand-held scraper, with minimal damage to the wall under the paint.
A sheet sander or random orbital sander. Start with 40 or 80 grit sanding paper.
A heatgun. Latex paint often bubbles and peels off when heated. It could be better to try this method in a small area to determine how thick your paint is. Heating an entire wall could be very time consuming and therefore not recommended.
An angle grinder with a paint removal disc (gentle), wire brush or a flap disk (destructive). It is likely to hurt the wall, so be extremely careful. I haven't seen any paint that can resist a 40 grit flap disk.
Or chemically, use a professional paint stripper instead of any cleaner or degreaser. Usually very effective, but remember to completely clean the stripper before repaint.