I use the Instead cups, and re-use them about ten times. I will probably be moving over to the diva cup soon, but I still have a whole box of insteads to go through.

To answer the public restroom question, I came up with a really good solution. I pack a sandwich baggie with a torn strip of newspaper folded up inside. I bring a clean Instead cup with me to work, and when it's time to swap, I empty the first, dab with toilet paper, wrap in the newspaper, put in the plastic sandwich bag. This easily slips into my pocket or bag. I get home and wash and rinse both bag and cup and chuck the newsprint. Seems like a pain but it really isn't. Although I guess the rinsing and washing does have some carbon footprint, it's better than landfilling wrappers and pads and tampons (in my mind.)

Non-painful placement of the cup is easy once you find your "rim bone" as my oby/gyn likes to call it when she prescribed me with my first diaphram. It's up and in toward the belly button, and a properly fitting Instead cup (not sure about diva and moon) sits right on that ledge. Getting it out is easy - go up to the ledge, scrunch like you are doing an ab crunch, and get a finger between you and the rim. Easy peasey (and practice makes perfect.)

Using a gel may help you with this. Although, I have a funny story about a slippery diaphram that got away from me once... I think it might be too much information, though!