Pores are not like doors

If consumers would only understand that pores are not like doors, they do not open and close.
What you are treating is the tissue surrounding the pore. When product is rich in filler such as petroleum this can cause asphyxiation of the pore. 

Should the filler remain in the pore it can cause the pore walls to stretch and become enlarged. Fillers will also create a build up on the skin much like floor wax.
The other hand of this is that products suggest that they will open the pore to remove the congestion within the pore. Again, the pore itself is not opening, products that will dissolve the cellular debris will soften the tissue surrounding the pore allowing for the congestion to be released.

Please do not fall into the marketing trap of believing the pores will open and the congestion will be magically released!