The spray might seem easier to apply HOWEVER think about this:
What happens when you spray it? answer: It floats and gets on everything else, like your glasses, your windshield, your partners glasses, all over the boat!
(So you have already lost some of the product in the air, so it's really not that cost effective!)
If you have an aerosol spray and the spray cap gets clogged then you have LOST the rest of the product.
Here at Kick'n Bass we will not sell a recognized defective application product, so we won't sell a spray application package. You can buy your own small spray bottles at the Walmart travel section, but even they will eventually clog up, BUT you could at least pour the product out and not loose your investment.
One of the simplest and easiest application methods is to put a few drops in your soft plastic bag. Just drop the lure back in the bag if you need it recharged. Kick'n Bass Attractants is an all natural fish oil based and lasts a very very long time. (Water based products have to be reapplied frequently.)
So take into consideration the "base" of the attractants that you use. Some have to be in the Gel form to last longer on the bait.
Even applying to hard baits the "drip drop" method works. Or a few drops in a bag, but be careful of the hooks. (Kick'n Bass is in the prostaff testing stage of a Solid Applicator that is easy to apply to hard baits. Initial results are amazing. One application can last all day.)
The primary answer to YOUR question is which of those actually work? So the packaging should not be of concern since you probably can't change the formula base of what you want to use.