well what i do is i take a comb with me and all throughout the con, (except for when photos or eating or fangirling is involved) i brush my wig.
it also tangles less often now cuz its used to being combed and so the fibers just stay flat.
so id be walking around with my comb just gently brushing my hair or something lol. if somehow ur wig gets tangly just go to the bathroom, yeah take the wig off, and brush it starting at the bottom and slowly working ur way up while holding it against the wall. if ur dedicated its easy as that without the need to buy any sort of spray bottle stuff.