Greetings, priest, from a fellow Canuck.

I believe SwampDonkey is correct in cautioning you about improvised weapons. Aside from prohibited items, anything used for offensive purposes can be considered a weapon under Canadian law. (If you use an item for legitimate self-defence, that of course is legally permissible, as long as you stop when the immediate threat is ended.)

It seems to me the solution to the problem needs to be a bit deeper than a bottle of spray-on goo.

If the club owners and bouncers aren't providing adequate security for their staff, that is a serious matter under your province's occupational health and safety legislation. If someone lays hands on you, that's assault, and it's actionable under law.

At least, ensure the lady has a safe route home. And get her into a less nasty job situation if you can.

That's my 2-cents' worth anyway.