Careful with that. I've researched it a bit and yes, the effects will last longer with a little glucose. But remember, glucose is a perfect growth medium. You might breed some kind of infection using that.......in some cases.
With saline solution (0.9%) it burns a little at first. Of course, the pressure arises, but that can also be horny. With glucose solution it should burn less, I will try that now for the first time.
With saline solution (0.9%), the effect is relatively short-lived. It should work better with glucose solution 5%. I received the first bottles of this solution today and will give it a try.