The way I look at it is in terms of pH. The higher the pH of your hair, the more the pores open. You could try using a dilute mixture of baking soda + water to increase pH before doing a DC or applying colour (i don't know about relaxer though). That way the pores are already more/ slightly more open than they would normally be.
I know it works for me anyway. If you give it a try and let me know how it works out for you.
I know it works for me anyway. If you give it a try and let me know how it works out for you.