The other variable is how bad with what is the blade. Maybe just some dust caught in dried and heated sap? If not too burned, a toothbrush and Simple Green works fine. Or even Windex, which I think has a little ammonia. For tougher jobs, soak in ammonia or TSP. Every other person will find the other one working better, probably because they're cleaning something slightly different.
OTOH, take the brand new Forrest 7-1/4 blade I put in my panel saw and cut some hardwood ply with. How was I to know they label the thing on the opposite side from standard 7-1/4 blades? While it still cut splinter free (backwards, amazing!), the side of the teeth was a solid black. Forget the toothbrush and Simple Green. Forget the ammonia or TSP. Soak in oven cleaner and then run the edge of a wood block over it to scrape off the remaining junk.
Blade is now sparkling clean and, in a couple of weeks I'm really looking forward to seeing how well it cuts in the other direction. Then I'll probably clean it with Simple Green.
GerryG