I'll put in my two cents on this.
First, I would say, there's nothing to "normalize" about tickling. It is normal, just as the vast majority of fetishes are normal, by which I'm guessing you mean acceptable to society in general.
Second, support each other in the community. Even within the tickling community there will be many varieties of what folks are into. I think it's okay to say, "sorry but I'm not into that" but blanket statements of a specific variant being "gross" somehow not to a specific liking doesn't help.
Third, work towards getting positive coverage of kinks and fetishes in media. Alternative sex and play practices discussed in media tend to fall into two camps: a complete joke to be laughed at or something that will lead you to death or to killing someone (added bonus if said kinkster is a murderer). When something kink-shaming comes up in media, speak up and tell why that is unacceptable.
Shameless plug: I created a card and dice game with the hopes of getting adults to recognize and understand kinks/fetishes as integral parts of human nature and a viable way of connecting with someone else in a relationship. I'm working towards gaining an audience and marketing it. Facebook page for "Kinksters" can be located here:
https://www.facebook.com/Kinksters-...Kinks-and-Couples-100800178987483/?tn-str=k*F
