Tickling is sexual for me, but I can see where you're coming from.
IMO, it's a fetish for some (like me); a sexy thing for others (analogous to sensual touching); a "relaxation" for others yet. It's just a matter of degree.
And sorry I have no idea where to find a "tickling for relaxation...
Greetings from Australia - long time lurker (nearly 10 years), occasional poster in past incarnations, first time posting as a Fish Head.
I moonlight as a photographer with the occasional after-hours material, including feet and tickling (on a strictly-fun basis). Mainly M/F 'ler.
Look forward...