starch is NOT sugar based either...it is corn starch usually and can attract bugs, usually silver fish, not ants...
and they are just trying to push the best press...which does not work any better or worse than simple vodka water or spray sizing!
starch can also dull your needles, flake off into your machine, dull your rotary blades, cause your blocks to come out wonky, makes a mess of your iron, and so on....
either way, each person has his/her own preference I am sure!