Because the super glue flows so freely (natural and the gel, although the gel is less so) I try to limit the size of the hole in the 3 g tube that feeds the glue. First I store the new tubes business end upright (in a clean yogurt cup). This gets the glue down in the tube so that when I make the hole, nothing comes out. To make sure, I give the still closed tube a few good swings in the air to really force the glue down in the tube. I then unscrew the applicator and puncture the business end with a needle. I like about a #27 gage hypodermic needle, but anything sharp and small will do, an ordinary small sewing needle, for instance. I've not found a hole to be too small, but a hole too big is an annoyance. I replace the applicator and use the system as is. The hole in the applicator is actually too big, but I haven't yet bothered to figure out a reliable system of making this hole smaller. I put up with the annoyance of having too big of a dispensing hole. All this is irrelevant to sealing wounds on cacti. Usually large amounts of glue are needed so too much doesn't matter. One has to apply the glue in some sort of pattern when there is a big wound to seal. That way, even as the glue in contact with the water in the plant is polymerizing like crazy, there is still some monomeric stuff handy to push onto an unsealed wound. There is enough optical difference between polymerized glue and wet unsealed cactus that one can tell what needs more glue. There is no harm in doing more than one pass with the glue. It binds well to already-polymerized glue skin. I've not found a perfect spreading applicator. It seems that anything capable of pushing the glue around will do. Where the size of the delivery bead matters is in grafting. There a too-big bead tends to work its way into the space between stock and scion, cutting off vascular communication and leading to graft failure.
Another virtue of the gel is that it does not regularly harden in the applicator tip after use. This not-hardening may last more than a week or two The ordinary super glue usually plugs up the tip within an hour or less. This plug must be pushed out with a needle before using the glue again.