it is a matter of patience. (or lack of ) i know a stringer who (used to) do the same as you. never use any tool other than the pliers. so it is possible to thread through any shared holes without an awl or string mover. my first attack is still the pliers as well as nudging the string by finger.
however, i usually can tell whether that hole is a stubborn one or not and i will resort to the awl if so. esp for rackets with fresher grommets, i just don't have much patience anymore.
Agree with Kwun. Anywhere you use string mover, you can use your thumb to move the string. Awl is last option but should not be ignored.
The string mover is definitely safer. I've never heard of a broken string from using it because tension was too high, and you probably shouldn't string over 30lbs anyways.
But I'd be curious to know if it ever happened.
I have snapped strings using the string mover before. It wasn't because I nicked it with the tip, it was actually while I was moving the mains with it as per my regular routine. The racquet was being strung in the lower 30s and the string just gave in. First and only time it has happened to me. I only use the string mover for blocked shares these days and it has never failed getting the string through for me. I have snapped mains several times sticking an awl through to widen the shared hole and I find that its an unsafe choice in this regard.
If its a blocked single cross hole due to the mains, then I usually try to widen either the top or the bottom with a small dull awl, whichever is already bigger. The important point is if its the top that is bigger, only push and rotate the awl against the top of the grommet and if its the bottom, then only push towards the bottom. There is also no need to stick the awl so far in that you see it sticking out from the other side of the grommet. Inserting only the tip is sufficient enough to create the effect. I then cut the strings at a sharp angle and push it through. If that fails, cut again, rotate the string and try at a different angle.
these days i use the awl instead of the string mover.
my awl is the Gamma one and has a very thin tip and shaft. it is perfect for badminton as it easily finds the gap between the string and grommet (by pointing it down) and i have never even once damage a string.
Never use an awl or a hook (anymore). Always cut the string in a tip, look through the hole to see in which direction I should put it in (Kwun's angle of attack), and then use pliers to push it through (if the string knicks, I cut it again). I have 100% success rate using these methods on 80+ jobs.
Just wait till you get 1400 rackets in the first 8 months of the year. You will have a few to give you a little trouble =)
The pathfinder is very useful usually for getting the string to come out of the racquet frame from a blocked hole. I use this only while stringing tennis racquets in the off chance pushing the string out with pliers don't work (which it usually does since tennis strings are much more rigid and stiff). The pathfinder is very much like an awl, but its a little bit thicker to accommodate having the string inside the tool. I don't think this would work on a badminton frame as the grommets are too small for the pathfinder tip to fit as well as the gauge of badminton string would be far too thin for the tool to grab onto. I'll have to test out this theory when I have the chance however.