Bedroom wall question

[Carlos B]

Hi,

I am decorating a bedroom and having hired a wallpaper steam-stripper to remove the wallpaper, I stripped the wallpaper. Once the wallpaper was off there were parts of the wall where there appeared to be a pink-ish layer, underneath that there was some brownish stuff. It all seemed pretty stuck on so I just sanded and cleaned. But when I started painting, the pinkish stuff and the brownish stuff just came off on to the roller. Underneath that there is a greyish layer which I think is the actual plaster. I'm guessing the brown stuff is old wallpaper paste, and i saw online that a good way to get rid of it is to use hot soapy water. I tried this - and it loosened the pink and brown layers a bit - but only slightly. How can I quickly get this large wall ready to paint?
I think my options are:
1) Hire or buy a steam stripper and use it to remove these layers, being careful not to destroy the underlying plaster.
2) Try a chemical approach, like sugar soap or stripper

Please see photos.

Please help.

Many thanks,

Carlos

 

[Iamchamps]

Get a plasterer in to skim it? Nice smooth and ready then.