The current prostitution laws in Canada are a response to the Supreme Court Decision to strike down the existing laws at the time in the case: https://en.wikipedia.org/wiki/Canada_(AG)_v_Bedford . Unfortunately, in 2014, the Conservatives were in power so they had to come up with a law to please their moron bible thumping supporters who think that if you make something illegal it won't happen! Therefore, the Cons basically ripped off the nordic laws from Scandinavia and made it the new law here.
The bottom line is that the new law doesn't really make any sense and the cops don't have the resources or the inclination to deal with it. The only risk of getting yourself busted is if you deal with street level prostitutes (which most likely doesn't involve texting) where the cops will sometimes enforce the law if they have received complaints from people living in the areas where the street level stuff happens. So stay away from that, which you should do anyways, and you're probably going to be fine.
The only exception to this is if the provider you messaged were the victim of some serious crime. For instance, if she disappeared or were murdered, then the cops would go through her phone and contact you to get information or rule you out as a suspect in regards to dealing with the case. If the police did this, they wouldn't be looking to bust you for a prostitution related offence, they would simply be trying to solve the serious case they are dealing with.
The bottom line is that the new law doesn't really make any sense and the cops don't have the resources or the inclination to deal with it. The only risk of getting yourself busted is if you deal with street level prostitutes (which most likely doesn't involve texting) where the cops will sometimes enforce the law if they have received complaints from people living in the areas where the street level stuff happens. So stay away from that, which you should do anyways, and you're probably going to be fine.
The only exception to this is if the provider you messaged were the victim of some serious crime. For instance, if she disappeared or were murdered, then the cops would go through her phone and contact you to get information or rule you out as a suspect in regards to dealing with the case. If the police did this, they wouldn't be looking to bust you for a prostitution related offence, they would simply be trying to solve the serious case they are dealing with.