The Keeper is made from natural latex/rubber, while the Diva (and i'm assuming Lunette) is silicone. Actually, latex would probably break down faster than silicone so if you've had yours for so many yrs, i'm sure the Diva should last longer.

The getting it out trick for me is to pinch and pull. While I'm sitting on the toilet I pinch the base where it's textured for my grip and then slowly pull it out making sure the cup tips into the toilet as it exits. Give it a moment to drain and then rinse it in the sink.

One of the tricks when putting it in is to fold in in 4th's and insert, allowing the cup to expand once it's halfway inside. Be sure it's expanded fully and not suctioned to your vaginal wall by running your finger around the base to feel if it's fully expanded. If it hasn't expanded then do the pinch grip and pull it out a little until it expands.

It takes a little getting used to but I found that using the Diva Cup actually reduces my craps and leaves me more fresh than tampons or the Instead cups.

I'll try the vinegar this week and see what I think.