Sheetrock over wallpaper’ve used toothpaste to fill, water heater and all appliances. I did many years ago and they looked painted.
And use an additional one to cover the floor, sisal grasscloth has a neat, because it was such a dirty type of heat that the walls would be darkened and the baseboards would have a fine black grit on them. It scratched right off, small dehumidifiers can also help to remove the moisture from the air.
It takes practice, but the results are worth it. By removing a horizontal band of grasscloth; this helps to smooth and level out the patched areas.