For hard lures
It's very rare to add attractant to a hard lure, since the surface of its body is smooth and most attractants don't last more than one cast. However, there are some very viscous attractants that dissolve very slowly in water, which are categorized as gel attractants. These are the only ones that hold up well on hard lures, but can also be used on other types of lure.
Of course, attractants are effective on hard lures in two specific cases: when fishing very slowly or when combing an area very precisely. Very slow fishing with hard lures, for example jerkbait suspending in winter, lends itself perfectly to the addition of attractant. When you're combing an area where the water isn't moving, even if you have to put attractant back on your lure often, you'll be saturating a surface with scent, which can trigger the appetite of inactive fish.
For soft lures
Most commercial soft lures are already sold in small watertight sachets filled with liquid attractant. However, if you use these lures frequently without losing them, the liquid will quickly disappear and become ineffective. You can then add more liquid attractant to the sachet so that the lures soak up the liquid. Be careful not to be too heavy-handed: the aim is not to bathe the lures in liquid, as the salt present in the material may absorb everything and cause the lure to swell.
If you've already thrown away the packaging and your soft lures are stored in boxes, use gel attractants instead, which you'll apply more or less generously to the body of the lure so that it diffuses the scent as it swims.
For skirted decoys
Skirted lures such as rubber jigs, chatterbaits or spinnerbaits are perfect candidates for adding attractants. The skirt, made up of numerous silicone strips, can easily hold a large quantity of attractant and spread it more or less rapidly depending on its viscosity.
Gel attractants are rather difficult to apply correctly, but their effectiveness over time will be increased tenfold. Liquid attractants are very easy to apply, both on the trailer and on the skirt, but will only be effective over a few casts. However, if you want to attack a remarkable spot where you know the potential to hold fish, liquid attractant will more easily trigger a hit, as it will diffuse very quickly over two or three casts.
