Well made short - you can level youre weapon skills inside Trial of the Champion HC..
I just cleared ToC HC today, and found myself idling with a RP polearm (farmer ftw)
I ran around spammin my spells, to find out i recieved weapon skills, if my Blade Barrier procced (having Blood Runes on CD) Blade Barrier - Spell - World of Warcraft
I havent rly tested it in any other instances, and honestly i cba to do that..
To make youre bladebarrier proc easily, use stuff like Blood Boil - Blood Tap - HoW etc. etc. almost every spell works, to proc it - to make youre weapon skill rise even faster... have fun..
Here´s a screenshot :
and meh offtopic some - been a member for 1 year now - i love this site, and i hope i finnaly bring something back for all the tricks you guys have taught me <3