I just use old dijon bottles with a bit left in it to get the rest out and shake the heck out of it but I go through a lot of mustard.
The lengths I’ve seen brands go To avoid having sugar as their 1st or 2nd ingredient…
after that you have invert sugar, corn syrup, molasses, brown rice syrup etc. as following ingredients…
A few years ago organic/natural products were marketed as containing "Evaporated Cane Juice" (aka Cane Sugar) but my understanding is the FDA put an end to that one.