This is traditionally vanilla custard, for the appearance that the wam-girl has been creampied. In the case of an anal lover, a squirting dildo with lube can also be attached.
It's worth noting that during this final, non humanoid dildos are often used for extra humiliation and pleasure- nothing quite spells out a wam-girl's future career like getting creampied by a canine, vibrating, knotting dong or a thick horsecock.
Those who pass this final test participate in a celebratory messy orgy. Toys of all kinds, squirting and not, are provided next to a massive inflatable pool of pudding. Divas encourage candidates to humiliate them, each other, and themselves.
Variations on the orgy have been made. Messy obstacle courses, with sexual rewards or forfeits, have been used.
Whatever the method, all too often new wam-girls pass out during the celebration. They often wake up strapped to some new device for further dirtying and degradation, but that's showbiz.