I think it depends. On my cheeks and chin it is easy to get BBS with a WTG pass but on my neck it is very difficult. I think it depends on how flat the hair grows to the skin.
On my cheeks the hair grows straight out almost, but on the neck my hair grows very flat and tends to grow back under the skin no matter how much I try when I go ATG - which is the only way I can get BBS there