Woodchip tends to be used to hide a multitude of sins with the wall finish underneath which can lead to requiring a full plaster skim once paper has been removed, however...
I would suggest avoiding the use of warm water as it tends to mix with the existing paste on the wall and turns everything to mush creating more work.
We tend use a paper scorer, Zinsser DIF Gel which breaks down the paste and a non metal scraper [Zinsser again] to avoid damaging the plasterwork underneath.
I would also advise against using a steamer unless you are prepared to have the walls re-plastered as they can pop the finish.
Hope this helps