I'm renovating an old Victorian house and have just scraped off wallpaper in one of the rooms. The walls are plaster and there are some cracks some hairline and some an inch wide with a few places that open up to about the size of a mouse pad. Also a couple of the corners had crumbled and are now dug out with trenches about an inch wide.
I was told that Durabond 90 is the best for plaster even though I don't see a lot of youtube videos showing Durabond being spread on a plaster wall. (maybe it has a differen't name in other countries?).

I went to the hardware store the guy their told me that Durabond 90 will work great and to just fill the cracks with it and skim coat. I asked him if I should wet the wall or tape anything and he said no. In fact I think he said that I can't put tape down with Durabond. Then I asked about sanding in case I can't get a decent enough finish and he said I could then skim coat another product over top and sand and if I did that I could tape over top of the Durabond with fibre tape and this second layer of joint compound or whatever it was (can't remember the name of it off hand).

I'm a little suspicious of his instructions. I really don't have to do any prep work other then vaccuming the cracks etc? Dont' need to wet the wall? I can't tape the cracks with fibre tape and durabond and then skim coat with more durabond? How can I tape after the durabond is on and dried and the cracks are no longer visable?