One important thing to note is that some of glue cotton swabs have very little or no glue at all holding the cotton on one side, but good glue amount on the other side. This means that sometimes cotton is very loose and could theoretically slide off in nasopharynx and get into the lungs.I recommend the once that use glue
I usually check that the cotton is firmly in place on the stick by rubbing it a bit with fingers. If it's not, then I use the other side or another swab. More costly brands will probably have better quality of glue.