Actually pussyeater prostitution in Canada is not illegal. Only communicating for the purposes, living off of the avails (i.e. pimping) or keeping a common bawdy house (or being found in one), are illegal. Actually performing sexual services for cash though (or paying for those services), nothing against the law there.
That's why outcalls are totally legal. Only once the girl is in the privacy of your room do you discuss sex and cash. It may be prostitution, but there is no communication about that until in private. But incalls could be a problem, since the sp's house could be deemed a bawdy house. Same with massage parlours that offer fs.
Having said that, I do agree with you that swining is a bit different than having a significant other that is a sp.
Tom