i know i'm a little late to this thread ...
a lot of times when I use headslick, I find that I don't always need a soothing aftershave. The menthol seems to be enough sooth the skin. Though, I always use a moisturizer afterwards.
Though, sometimes if i forgot to change blade cartridges and my head gets a little raw, I tend to use taylor of old bond street shaving shop aftershave gel or Game Day mens aftershave because they don't have alcohol.