I've never used slab sauce but plenty of others. The problem is they're oily/greasy and you're not gonna get it out of the jig completely. As long as it's not matted down while in the water fishing you're good to go.
I recommend applying scents to the chenille and on hair jigs I push the hair back to open up them up a bit and squirt it inside by the head/collar/hook shank then mash it in a bit. On big bucktail jigs I rub scent into the sides 1/4-1/2" from the collar. The hair will naturally hold it. The slick painted head won't hold it long.
I've used Dawn dish detergent to wash greasy Pro Cure menhaden scent out of $$ bucktails I tie for offshore jigging and caught fish the next trip. Wash well, pat dry then hang to dry, then put in your tackle box only once 100% dry or you'll start rusting things.