Blue LT is fine, just a 1/4 drop or less is needed for any single thread on a S&W revolver. A heat gun will loosen it's grip if you use too much.
A DIY trigger job is easy, rewarding and saves you alot of money. Stay away from files or stones unless you know what your doing. Cleaning, polishing and very
light oil in addition to lighter rebound spring and lighter hammer leaf and/or knocking down and angling the hammer leaf tension screw. Polish outside of rebound spring and hammer leaf spring also.
Brownells sells an inexpensive rebound spring tool, buy it. Thing is worth it's weight in gold. www.gunsprings.com
has the springs and leafs. I like the variety pack of rebound springs. I think 11# is the lightest they sell. For a SD revolver, 13-14# is nice, any lighter and trigger does'nt reset fast enough in DA. 11# is nice for SA hunting, target work. I also prefer stock hammer spring with filed tension screw opposed to the "tinny" sound the Wolff makes. They're also smoother IMO.