Is your hot end jammed? A useful tool is a 8" - 200mm long piece of bicycle brake cable. The diameter is just a bit smaller than 1.75mm and it’s flexible enough to feed through the opened extruder into the hot end yet stiff enough to push out melted filament. The kicker is, being metal it absorbs and distributes heat through itself so when the cable hits the clog of filament that melted from heat creep and then resolidified above the heat break, it not only penetrates the clog, but spreads heat into it allowing it to be pushed out by running the cable in and out.
Sounds like a good way to scratch the inside of your barrel. I have, as a last resort before disassembling, pushed a 1.5mm (actually the imperial equivalent, as I actually use the metric ones) hex driver with the tip heated with a butane torch to break through a plug to clear it. This should be kinder to the interior surface of your barrel, as a hex wrench (especially a ball-tipped one) doesn’t have such sharp edges.
@Whosa_whatsis it was on my old vanilla buko if I remember right. 
This method works well if a nylon cold pull doesn’t suffice.
@Ben_Van_Den_Broeck I’ve done it a couple of times since then. This is for when you can’t get the nylon to go in hot so that you can pull it out cold.
Well, if you don’t have any nylon it’s a last resort. Granted, use of a proper bike cable cutter is imperative to this plan. If you don’t use a proper bike cable cutter the cable end would be dangerously sharp.
If you don´t have nylon go to the hardware store and buy some trimmerline. Cheap and works very well.
Funny thing - due to stupidity on my part I was struggling with a completely abs plugged barrel today. I discovered something called “Doll Needles” in the crafts department and the medium size was 1.68mm at the width of the eyelet, and completely smooth chrome plated with nothing that could possibly scratch the inside of my new Hexagon head. Heated the barrel up with a torch while it was loosely held in a clamp, grabbed the needle in vise grips and ran it through, and cleaned up the residue with a quick soak in acetone. Worked great! And less than 2 bucks for a 5 pack.