I personally worked on different canvassing jobs for 5 years. I have to tell you it gets you no where. And may even hurt future employment opportunities. By that I mean, You can't get promoted when you canvass because it's like a slavery job as you mentioned. The boss will do whatever he/she wants with you. It may hurt your employment record because canvassing is NOT a permanent job. It can leave gaps on your employment record. That is not good for employers who look at work history. Not many employers will take canvassing as experience at all. Not even sales people. Canvassing is just a way of exploiting people for money or votes. I think you are better than that. Avoid it.