(From my understanding) Under the OGL, I can use open content created by another publisher if the author has designated that item as open content under the OGL.
However this becomes muddled when someone puts up "homebrew". I would normally credit them under section 15 of my OGL posting, however many of those who post homebrew do not do so explicitly under the OGL.
I realize that easiest (and probably best) answer is, "Don't take inspiration from Homebrew." but using my example, I would almost feel barred from ever using a crossbow that added a characters strength to damage because I first saw it in Kirthfinder.
Since Homebrewers are using OGC, is their work legally implied to be Open Content?
Has anyone else ran into this problem? Is there any advice/rules of thumb I should follow?