I've sold many things on OLX, using it since 2 years.
The best part is that most of the times you get potential buyers over here. They are ready to buy you product at your price ( most of the times) , sometimes a little negotiation works.
Posting on this app is ever easy with the new update. Now I just have to click a photo of my product and post it. Rest everything is done by their team, they decide the title and category of your product and post it after a review of it. It doesn't take more than 10 minutes for them to review it.
Most of the times I get response from the buyers. But sometimes they just come to your place, check everything deeply and then just leave by saying they do not want to buy it. Which actually what I feel is waste of time.
But yeah, it works most of the times. I would recommend you all to use this app once atleast! I am sure it will help you get rid of your old products.