if only stay a month, not big problem, Chinese customers officer have no time to trouble you, I believe they know everything.
The worse case is: illegal to stay in China, pay a fine ($$$/day), and maybe asked to withdraw your China Hu-ko if you have.
No any problem to enter US and Canada with your Canadian passport.
Maybe you can travel to HomgKong with Chinese passport first, then
fly to Canada or US with your Canadian passport.
For long term, better to use your Canadian passport.